diff --git a/aiogram/bot/api.py b/aiogram/bot/api.py
index f287e32f..6089dcbf 100644
--- a/aiogram/bot/api.py
+++ b/aiogram/bot/api.py
@@ -166,7 +166,10 @@ def compose_data(params=None, files=None):
 
     if params:
         for key, value in params.items():
-            data.add_field(key, str(value))
+            if isinstance(value, (list, dict)):
+                data.add_field(key, json.dumps(value))
+            else:
+                data.add_field(key, str(value))
 
     if files:
         for key, f in files.items():