diff --git a/backend/app.py b/backend/app.py
index 4f0cb41..2e5e3fa 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -3192,10 +3192,22 @@ def api_animal_chat():
 {chr(10).join(product_lines)}
 """
         
+        # 벡터 DB 검색 (LanceDB RAG)
+        vector_context = ""
+        try:
+            from utils.animal_rag import get_animal_rag
+            # 마지막 사용자 메시지로 검색
+            last_user_msg = next((m['content'] for m in reversed(messages) if m.get('role') == 'user'), '')
+            if last_user_msg:
+                rag = get_animal_rag()
+                vector_context = rag.get_context_for_chat(last_user_msg, n_results=3)
+        except Exception as e:
+            logging.warning(f"벡터 검색 실패 (무시): {e}")
+        
         # System Prompt 구성
         system_prompt = ANIMAL_CHAT_SYSTEM_PROMPT.format(
             available_products=available_products_text,
-            knowledge_base=ANIMAL_DRUG_KNOWLEDGE
+            knowledge_base=ANIMAL_DRUG_KNOWLEDGE + "\n\n" + vector_context if vector_context else ANIMAL_DRUG_KNOWLEDGE
         )
         
         # OpenAI API 호출
diff --git a/backend/db/chroma_test/b8ea4b8e-64ae-4206-b633-d732b5ddf6ae/data_level0.bin b/backend/db/chroma_test/b8ea4b8e-64ae-4206-b633-d732b5ddf6ae/data_level0.bin
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diff --git a/backend/db/lance_animal_drugs/animal_drugs.lance/_transactions/0-933ff3c4-220e-4547-ab20-88bb9eb16945.txn b/backend/db/lance_animal_drugs/animal_drugs.lance/_transactions/0-933ff3c4-220e-4547-ab20-88bb9eb16945.txn
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diff --git a/backend/db/lance_animal_drugs/animal_drugs.lance/_versions/18446744073709551614.manifest b/backend/db/lance_animal_drugs/animal_drugs.lance/_versions/18446744073709551614.manifest
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diff --git a/backend/db/lance_animal_drugs/animal_drugs.lance/data/011101011010000111010000397df14425939449f00bbdc140.lance b/backend/db/lance_animal_drugs/animal_drugs.lance/data/011101011010000111010000397df14425939449f00bbdc140.lance
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diff --git a/backend/test_chroma.py b/backend/test_chroma.py
new file mode 100644
index 0000000..6e8bddb
--- /dev/null
+++ b/backend/test_chroma.py
@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+import os
+from dotenv import load_dotenv
+load_dotenv()
+
+import chromadb
+
+print('1. creating client...', flush=True)
+client = chromadb.PersistentClient(path='./db/chroma_test3')
+print('2. client created', flush=True)
+
+# 임베딩 없이 컬렉션 생성
+col = client.get_or_create_collection('test3')
+print('3. collection created (no ef)', flush=True)
+
+col.add(ids=['1'], documents=['hello world'], embeddings=[[0.1]*384])
+print('4. document added with manual embedding', flush=True)
+
+result = col.query(query_embeddings=[[0.1]*384], n_results=1)
+print(f'5. query result: {len(result["documents"][0])} docs', flush=True)
+print('Done!')
diff --git a/backend/test_rag.py b/backend/test_rag.py
new file mode 100644
index 0000000..8be18b5
--- /dev/null
+++ b/backend/test_rag.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+import sys
+import os
+sys.path.insert(0, os.path.dirname(__file__))
+
+print("1. Starting...")
+print(f"   CWD: {os.getcwd()}")
+
+from dotenv import load_dotenv
+load_dotenv()
+print(f"2. API Key: {os.getenv('OPENAI_API_KEY', 'NOT SET')[:20]}...")
+
+from utils.animal_rag import AnimalDrugRAG
+print("3. Module imported")
+
+rag = AnimalDrugRAG()
+print("4. RAG created")
+
+try:
+    count = rag.index_md_files()
+    print(f"5. Indexed: {count} chunks")
+except Exception as e:
+    print(f"5. Error: {e}")
+    import traceback
+    traceback.print_exc()
+
+print("6. Done")
diff --git a/backend/test_rag_output.txt b/backend/test_rag_output.txt
new file mode 100644
index 0000000..e69de29
diff --git a/backend/utils/animal_rag.py b/backend/utils/animal_rag.py
new file mode 100644
index 0000000..6aa9568
--- /dev/null
+++ b/backend/utils/animal_rag.py
@@ -0,0 +1,339 @@
+# -*- coding: utf-8 -*-
+"""
+동물약 벡터 DB RAG 모듈
+- LanceDB + OpenAI text-embedding-3-small
+- MD 파일 청킹 및 임베딩
+- 유사도 검색
+"""
+
+import os
+import re
+import logging
+from pathlib import Path
+from typing import List, Dict, Optional
+
+# .env 로드
+from dotenv import load_dotenv
+env_path = Path(__file__).parent.parent / ".env"
+load_dotenv(env_path)
+
+# LanceDB
+import lancedb
+from openai import OpenAI
+
+logger = logging.getLogger(__name__)
+
+# 설정
+LANCE_DB_PATH = Path(__file__).parent.parent / "db" / "lance_animal_drugs"
+MD_DOCS_PATH = Path("C:/Users/청춘약국/source/new_anipharm")
+TABLE_NAME = "animal_drugs"
+CHUNK_SIZE = 1500  # 약 500 토큰
+CHUNK_OVERLAP = 300  # 약 100 토큰
+EMBEDDING_DIM = 1536  # text-embedding-3-small
+
+
+class AnimalDrugRAG:
+    """동물약 RAG 클래스 (LanceDB 버전)"""
+    
+    def __init__(self, openai_api_key: str = None):
+        """
+        Args:
+            openai_api_key: OpenAI API 키 (없으면 환경변수에서 가져옴)
+        """
+        self.api_key = openai_api_key or os.getenv('OPENAI_API_KEY')
+        self.db = None
+        self.table = None
+        self.openai_client = None
+        self._initialized = False
+        
+    def _init_db(self):
+        """DB 초기화 (lazy loading)"""
+        if self._initialized:
+            return
+            
+        try:
+            # LanceDB 연결
+            LANCE_DB_PATH.mkdir(parents=True, exist_ok=True)
+            self.db = lancedb.connect(str(LANCE_DB_PATH))
+            
+            # OpenAI 클라이언트
+            if self.api_key:
+                self.openai_client = OpenAI(api_key=self.api_key)
+            else:
+                logger.warning("OpenAI API 키 없음")
+            
+            # 기존 테이블 열기
+            if TABLE_NAME in self.db.table_names():
+                self.table = self.db.open_table(TABLE_NAME)
+                logger.info(f"기존 테이블 열림 (행 수: {len(self.table)})")
+            else:
+                logger.info("테이블 없음 - index_md_files() 호출 필요")
+                
+            self._initialized = True
+            
+        except Exception as e:
+            logger.error(f"AnimalDrugRAG 초기화 실패: {e}")
+            raise
+    
+    def _get_embedding(self, text: str) -> List[float]:
+        """OpenAI 임베딩 생성"""
+        if not self.openai_client:
+            raise ValueError("OpenAI 클라이언트 없음")
+            
+        response = self.openai_client.embeddings.create(
+            model="text-embedding-3-small",
+            input=text
+        )
+        return response.data[0].embedding
+    
+    def _get_embeddings_batch(self, texts: List[str]) -> List[List[float]]:
+        """배치 임베딩 생성"""
+        if not self.openai_client:
+            raise ValueError("OpenAI 클라이언트 없음")
+        
+        # OpenAI는 한 번에 최대 2048개 텍스트 처리
+        embeddings = []
+        batch_size = 100
+        
+        for i in range(0, len(texts), batch_size):
+            batch = texts[i:i+batch_size]
+            response = self.openai_client.embeddings.create(
+                model="text-embedding-3-small",
+                input=batch
+            )
+            embeddings.extend([d.embedding for d in response.data])
+            logger.info(f"임베딩 생성: {i+len(batch)}/{len(texts)}")
+        
+        return embeddings
+    
+    def chunk_markdown(self, content: str, source_file: str) -> List[Dict]:
+        """
+        마크다운 청킹 (섹션 기반)
+        """
+        chunks = []
+        
+        # ## 헤더 기준 분리
+        sections = re.split(r'\n(?=## )', content)
+        
+        for i, section in enumerate(sections):
+            if not section.strip():
+                continue
+                
+            # 섹션 제목 추출
+            title_match = re.match(r'^## (.+?)(?:\n|$)', section)
+            section_title = title_match.group(1).strip() if title_match else f"섹션{i+1}"
+            
+            # 큰 섹션은 추가 분할
+            if len(section) > CHUNK_SIZE:
+                sub_chunks = self._split_by_size(section, CHUNK_SIZE, CHUNK_OVERLAP)
+                for j, sub_chunk in enumerate(sub_chunks):
+                    chunk_id = f"{source_file}#{section_title}#{j}"
+                    chunks.append({
+                        "id": chunk_id,
+                        "text": sub_chunk,
+                        "source": source_file,
+                        "section": section_title,
+                        "chunk_index": j
+                    })
+            else:
+                chunk_id = f"{source_file}#{section_title}"
+                chunks.append({
+                    "id": chunk_id,
+                    "text": section,
+                    "source": source_file,
+                    "section": section_title,
+                    "chunk_index": 0
+                })
+        
+        return chunks
+    
+    def _split_by_size(self, text: str, size: int, overlap: int) -> List[str]:
+        """텍스트를 크기 기준으로 분할"""
+        chunks = []
+        start = 0
+        
+        while start < len(text):
+            end = start + size
+            
+            # 문장 경계에서 자르기
+            if end < len(text):
+                last_break = text.rfind('\n', start, end)
+                if last_break == -1:
+                    last_break = text.rfind('. ', start, end)
+                if last_break > start + size // 2:
+                    end = last_break + 1
+            
+            chunks.append(text[start:end])
+            start = end - overlap
+            
+        return chunks
+    
+    def index_md_files(self, md_path: Path = None) -> int:
+        """
+        MD 파일들을 인덱싱
+        """
+        self._init_db()
+        
+        md_path = md_path or MD_DOCS_PATH
+        if not md_path.exists():
+            logger.error(f"MD 파일 경로 없음: {md_path}")
+            return 0
+        
+        # 기존 테이블 삭제
+        if TABLE_NAME in self.db.table_names():
+            self.db.drop_table(TABLE_NAME)
+            logger.info("기존 테이블 삭제")
+        
+        # 모든 청크 수집
+        all_chunks = []
+        md_files = list(md_path.glob("*.md"))
+        
+        for md_file in md_files:
+            try:
+                content = md_file.read_text(encoding='utf-8')
+                chunks = self.chunk_markdown(content, md_file.name)
+                all_chunks.extend(chunks)
+                logger.info(f"청킹: {md_file.name} ({len(chunks)}개)")
+            except Exception as e:
+                logger.error(f"청킹 실패 ({md_file.name}): {e}")
+        
+        if not all_chunks:
+            logger.warning("청크 없음")
+            return 0
+        
+        # 임베딩 생성
+        texts = [c["text"] for c in all_chunks]
+        logger.info(f"총 {len(texts)}개 청크 임베딩 시작...")
+        embeddings = self._get_embeddings_batch(texts)
+        
+        # 데이터 준비
+        data = []
+        for chunk, emb in zip(all_chunks, embeddings):
+            data.append({
+                "id": chunk["id"],
+                "text": chunk["text"],
+                "source": chunk["source"],
+                "section": chunk["section"],
+                "chunk_index": chunk["chunk_index"],
+                "vector": emb
+            })
+        
+        # 테이블 생성
+        self.table = self.db.create_table(TABLE_NAME, data)
+        logger.info(f"인덱싱 완료: {len(data)}개 청크")
+        
+        return len(data)
+    
+    def search(self, query: str, n_results: int = 3) -> List[Dict]:
+        """
+        유사도 검색
+        """
+        self._init_db()
+        
+        if self.table is None:
+            logger.warning("테이블 없음 - index_md_files() 필요")
+            return []
+        
+        try:
+            # 쿼리 임베딩
+            query_emb = self._get_embedding(query)
+            
+            # 검색
+            results = self.table.search(query_emb).limit(n_results).to_list()
+            
+            output = []
+            for r in results:
+                output.append({
+                    "text": r["text"],
+                    "source": r["source"],
+                    "section": r["section"],
+                    "score": 1 - r.get("_distance", 0)  # 거리 → 유사도
+                })
+            
+            return output
+            
+        except Exception as e:
+            logger.error(f"검색 실패: {e}")
+            return []
+    
+    def get_context_for_chat(self, query: str, n_results: int = 3) -> str:
+        """
+        챗봇용 컨텍스트 생성
+        """
+        results = self.search(query, n_results)
+        
+        if not results:
+            return ""
+        
+        context_parts = ["## 📚 관련 문서 (RAG 검색 결과)"]
+        
+        for i, r in enumerate(results, 1):
+            source = r["source"].replace(".md", "")
+            section = r["section"]
+            score = r["score"]
+            text = r["text"][:1500]
+            
+            context_parts.append(f"\n### [{i}] {source} - {section} (관련도: {score:.0%})")
+            context_parts.append(text)
+        
+        return "\n".join(context_parts)
+    
+    def get_stats(self) -> Dict:
+        """통계 정보 반환"""
+        self._init_db()
+        
+        count = len(self.table) if self.table else 0
+        return {
+            "table_name": TABLE_NAME,
+            "document_count": count,
+            "db_path": str(LANCE_DB_PATH)
+        }
+
+
+# 싱글톤 인스턴스
+_rag_instance: Optional[AnimalDrugRAG] = None
+
+
+def get_animal_rag(api_key: str = None) -> AnimalDrugRAG:
+    """싱글톤 RAG 인스턴스 반환"""
+    global _rag_instance
+    if _rag_instance is None:
+        _rag_instance = AnimalDrugRAG(api_key)
+    return _rag_instance
+
+
+# CLI 테스트
+if __name__ == "__main__":
+    import sys
+    
+    logging.basicConfig(level=logging.INFO)
+    
+    rag = AnimalDrugRAG()
+    
+    if len(sys.argv) > 1:
+        cmd = sys.argv[1]
+        
+        if cmd == "index":
+            count = rag.index_md_files()
+            print(f"\n✅ {count}개 청크 인덱싱 완료")
+            
+        elif cmd == "search" and len(sys.argv) > 2:
+            query = " ".join(sys.argv[2:])
+            results = rag.search(query)
+            print(f"\n🔍 검색: {query}")
+            for r in results:
+                print(f"\n[{r['score']:.0%}] {r['source']} - {r['section']}")
+                print(r['text'][:300] + "...")
+                
+        elif cmd == "stats":
+            stats = rag.get_stats()
+            print(f"\n📊 통계:")
+            print(f"  - 테이블: {stats['table_name']}")
+            print(f"  - 문서 수: {stats['document_count']}")
+            print(f"  - DB 경로: {stats['db_path']}")
+            
+    else:
+        print("사용법:")
+        print("  python animal_rag.py index        # MD 파일 인덱싱")
+        print("  python animal_rag.py search 질문  # 검색")
+        print("  python animal_rag.py stats        # 통계")