diff --git a/backend/app/services/korea_investment_api_adapter.py b/backend/app/services/korea_investment_api_adapter.py
new file mode 100644
index 0000000..1f8323e
--- /dev/null
+++ b/backend/app/services/korea_investment_api_adapter.py
@@ -0,0 +1,106 @@
+"""
+Korea Investment API Adapter
+기존 코드와의 호환성을 위한 어댑터
+
+기존: from app.services.korea_investment_api import korea_investment_api
+새 구조: app.trading.모듈로 분리
+
+이 파일은 기존 코드가 수정 없이 동작하도록 보장합니다.
+"""
+from typing import Dict, Any, Optional
+import logging
+
+from app.trading.kis_client import kis_client, real_market_client
+from app.trading.order_manager import order_manager
+from app.trading.market_data import market_data_provider
+
+logger = logging.getLogger(__name__)
+
+
+class KoreaInvestmentAPIAdapter:
+    """기존 API 인터페이스 어댑터 (Backward Compatibility)"""
+
+    def __init__(self):
+        self.client = kis_client
+        self.order_mgr = order_manager
+        self.market_data = market_data_provider
+        
+        # 기존 속성 노출
+        self.base_url = self.client.base_url
+        self.app_key = self.client.app_key
+        self.app_secret = self.client.app_secret
+        self.account_number = self.client.account_number
+        self.access_token = self.client.access_token
+        self.token_expires_at = self.client.token_expires_at
+
+    @classmethod
+    def for_real_market_data(cls) -> "KoreaInvestmentAPIAdapter":
+        """실계좌 시세조회 전용"""
+        instance = cls()
+        instance.client = real_market_client
+        instance.market_data = market_data_provider  # real_client 사용
+        return instance
+
+    # ── 주문 관련 (위임) ────────────────────────────────────────────
+    async def place_order(self, stock_code: str, order_type: str, quantity: int, price: Optional[float] = None):
+        return await self.order_mgr.place_order(stock_code, order_type, quantity, price)
+
+    async def cancel_order(self, order_id: str, quantity: int):
+        return await self.order_mgr.cancel_order(order_id, quantity)
+
+    async def get_balance(self):
+        return await self.order_mgr.get_balance()
+
+    async def place_overseas_order(self, symbol: str, order_type: str, quantity: int, price: float, exchange_code: str = "NASD"):
+        return await self.order_mgr.place_overseas_order(symbol, order_type, quantity, price, exchange_code)
+
+    async def get_overseas_balance(self):
+        return await self.order_mgr.get_overseas_balance()
+
+    # ── 시세/차트 관련 (위임) ─────────────────────────────────────
+    async def get_current_price(self, stock_code: str):
+        return await self.market_data.get_current_price(stock_code)
+
+    async def get_daily_chart(self, stock_code: str, period: str = "D", limit: int = 240):
+        return await self.market_data.get_daily_chart(stock_code, period, limit)
+
+    async def get_minute_chart(self, stock_code: str, ref_time: str = "", include_past: bool = True):
+        return await self.market_data.get_minute_chart(stock_code, ref_time, include_past)
+
+    async def get_overseas_price(self, symbol: str, exchange_code: str = "NASD"):
+        return await self.market_data.get_overseas_price(symbol, exchange_code)
+
+    async def get_orderbook(self, stock_code: str):
+        return await self.market_data.get_orderbook(stock_code)
+
+    async def get_volume_rank(self, market: str = "J"):
+        return await self.market_data.get_volume_rank(market)
+
+    async def get_stock_list(self, market: str = "J"):
+        return await self.market_data.get_volume_rank(market)
+
+    # ── 기타 (호환성) ───────────────────────────────────────────────
+    async def _get_access_token(self):
+        """Deprecated: 직접 호출 불필요 (client가 자동 관리)"""
+        return await self.client.get_access_token()
+
+    async def _make_request(self, method: str, endpoint: str, tr_id: str, extra_headers: Optional[Dict] = None, **kwargs):
+        """Deprecated: 직접 request 호출"""
+        return await self.client.request(method, endpoint, tr_id, extra_headers, **kwargs)
+
+    def get_monitor_stats(self):
+        """API 통계 (향후 monitoring.py로 이동 예정)"""
+        return {"message": "Monitoring moved to trading.monitoring module"}
+
+
+# 싱글톤 인스턴스 - 기존 코드에서 그대로 사용 가능
+korea_investment_api = KoreaInvestmentAPIAdapter()
+
+try:
+    real_market_api = KoreaInvestmentAPIAdapter.for_real_market_data()
+except Exception:
+    real_market_api = None
+
+
+# Backward compatibility alias
+KoreaInvestmentAPI = KoreaInvestmentAPIAdapter