diff --git a/main.py b/main.py
index 1d7a07f75..52680e7fc 100644
--- a/main.py
+++ b/main.py
@@ -15,17 +15,18 @@
 from src.models import OpenAIModel
 from src.memory import Memory
 from src.logger import logger
-from src.storage import Storage
+from src.storage import Storage, FileStorage, MongoStorage
 from src.utils import get_role_and_content
 from src.service.youtube import Youtube, YoutubeTranscriptReader
 from src.service.website import Website, WebsiteReader
+from src.mongodb import mongodb
 
 load_dotenv('.env')
 
 app = Flask(__name__)
 line_bot_api = LineBotApi(os.getenv('LINE_CHANNEL_ACCESS_TOKEN'))
 handler = WebhookHandler(os.getenv('LINE_CHANNEL_SECRET'))
-storage = Storage('db.json')
+storage = None
 youtube = Youtube(step=4)
 website = Website()
 
@@ -62,8 +63,9 @@ def handle_text_message(event):
             if not is_successful:
                 raise ValueError('Invalid API token')
             model_management[user_id] = model
-            api_keys[user_id] = api_key
-            storage.save(api_keys)
+            storage.save({
+                user_id: api_key
+            })
             msg = TextSendMessage(text='Token 有效，註冊成功')
 
         elif text.startswith('/指令說明'):
@@ -180,6 +182,11 @@ def home():
 
 
 if __name__ == "__main__":
+    if os.getenv('USE_MONGO'):
+        mongodb.connect_to_database()
+        storage = Storage(MongoStorage(mongodb.db))
+    else:
+        storage = Storage(FileStorage('db.json'))
     try:
         data = storage.load()
         for user_id in data.keys():
diff --git a/src/mongodb.py b/src/mongodb.py
new file mode 100644
index 000000000..de9e79400
--- /dev/null
+++ b/src/mongodb.py
@@ -0,0 +1,23 @@
+import os
+
+from pymongo import MongoClient
+
+
+class MongoDB():
+    """
+    Environment Variables:
+        MONGODB__PATH
+        MONGODB__DBNAME
+    """
+    client: None
+    db: None
+
+    def connect_to_database(self, mongo_path=None, db_name=None):
+        mongo_path = mongo_path or os.getenv('MONGODB__PATH')
+        db_name = db_name or os.getenv('MONGODB__DBNAME')
+        self.client = MongoClient(mongo_path)
+        assert self.client.config.command('ping')['ok'] == 1.0
+        self.db = self.client[db_name]
+
+
+mongodb = MongoDB()
diff --git a/src/storage.py b/src/storage.py
index d4ac6b3e8..2739efd03 100644
--- a/src/storage.py
+++ b/src/storage.py
@@ -1,15 +1,54 @@
 import json
+import datetime
 
 
-class Storage():
+class FileStorage:
     def __init__(self, file_name):
         self.fine_name = file_name
+        self.history = {}
 
     def save(self, data):
+        self.history.update(data)
         with open(self.fine_name, 'w', newline='') as f:
-            json.dump(data, f)
+            json.dump(self.history, f)
 
     def load(self):
         with open(self.fine_name, newline='') as jsonfile:
             data = json.load(jsonfile)
-        return data
+        self.history = data
+        return self.history
+
+
+class MongoStorage:
+    def __init__(self, db):
+        self.db = db
+
+    def save(self, data):
+        user_id, api_key = list(data.items())[0]
+        self.db['api_key'].update_one({
+            'user_id': user_id
+        }, {
+            '$set': {
+                'user_id': user_id,
+                'api_key': api_key,
+                'created_at': datetime.datetime.utcnow()
+            }
+        }, upsert=True)
+
+    def load(self):
+        data = list(self.db['api_key'].find())
+        res = {}
+        for i in range(len(data)):
+            res[data[i]['user_id']] = data[i]['api_key']
+        return res
+
+
+class Storage:
+    def __init__(self, storage):
+        self.storage = storage
+
+    def save(self, data):
+        self.storage.save(data)
+
+    def load(self):
+        return self.storage.load()