diff --git a/src/database.py b/src/database.py
new file mode 100644
index 0000000..cafa1ea
--- /dev/null
+++ b/src/database.py
@@ -0,0 +1,72 @@
+import json
+from datetime import datetime, timezone
+from notion_client import Client
+from loguru import logger
+
+
+class TradeRepository:
+    """Notion 데이터베이스에 거래 이력을 저장하는 레포지토리."""
+
+    def __init__(self, token: str, database_id: str):
+        self.client = Client(auth=token)
+        self.database_id = database_id
+
+    def save_trade(
+        self,
+        symbol: str,
+        side: str,
+        entry_price: float,
+        quantity: float,
+        leverage: int,
+        signal_data: dict = None,
+    ) -> dict:
+        properties = {
+            "Symbol": {"title": [{"text": {"content": symbol}}]},
+            "Side": {"select": {"name": side}},
+            "Entry Price": {"number": entry_price},
+            "Quantity": {"number": quantity},
+            "Leverage": {"number": leverage},
+            "Status": {"select": {"name": "OPEN"}},
+            "Signal Data": {
+                "rich_text": [
+                    {"text": {"content": json.dumps(signal_data or {}, ensure_ascii=False)}}
+                ]
+            },
+            "Opened At": {
+                "date": {"start": datetime.now(timezone.utc).isoformat()}
+            },
+        }
+        result = self.client.pages.create(
+            parent={"database_id": self.database_id},
+            properties=properties,
+        )
+        logger.info(f"거래 저장: {result['id']}")
+        return result
+
+    def close_trade(self, trade_id: str, exit_price: float, pnl: float) -> dict:
+        properties = {
+            "Exit Price": {"number": exit_price},
+            "PnL": {"number": pnl},
+            "Status": {"select": {"name": "CLOSED"}},
+            "Closed At": {
+                "date": {"start": datetime.now(timezone.utc).isoformat()}
+            },
+        }
+        result = self.client.pages.update(
+            page_id=trade_id,
+            properties=properties,
+        )
+        logger.info(f"거래 종료: {trade_id}, PnL: {pnl:.4f}")
+        return result
+
+    def get_open_trades(self, symbol: str) -> list[dict]:
+        response = self.client.databases.query(
+            database_id=self.database_id,
+            filter={
+                "and": [
+                    {"property": "Symbol", "title": {"equals": symbol}},
+                    {"property": "Status", "select": {"equals": "OPEN"}},
+                ]
+            },
+        )
+        return response.get("results", [])
diff --git a/tests/test_database.py b/tests/test_database.py
new file mode 100644
index 0000000..1b29d90
--- /dev/null
+++ b/tests/test_database.py
@@ -0,0 +1,42 @@
+import pytest
+from unittest.mock import MagicMock, patch
+from src.database import TradeRepository
+
+
+@pytest.fixture
+def mock_repo():
+    with patch("src.database.Client") as mock_client_cls:
+        mock_client = MagicMock()
+        mock_client_cls.return_value = mock_client
+        repo = TradeRepository(token="secret_test", database_id="db_test")
+        repo.client = mock_client
+        yield repo
+
+
+def test_save_trade(mock_repo):
+    mock_repo.client.pages.create.return_value = {
+        "id": "abc123",
+        "properties": {},
+    }
+    result = mock_repo.save_trade(
+        symbol="XRPUSDT",
+        side="LONG",
+        entry_price=0.5,
+        quantity=400.0,
+        leverage=10,
+        signal_data={"rsi": 32, "macd_hist": 0.001},
+    )
+    assert result["id"] == "abc123"
+
+
+def test_close_trade(mock_repo):
+    mock_repo.client.pages.update.return_value = {
+        "id": "abc123",
+        "properties": {
+            "Status": {"select": {"name": "CLOSED"}},
+        },
+    }
+    result = mock_repo.close_trade(
+        trade_id="abc123", exit_price=0.55, pnl=20.0
+    )
+    assert result["id"] == "abc123"