diff --git a/ptuning/main.py b/ptuning/main.py
index b027e9e..6328eac 100644
--- a/ptuning/main.py
+++ b/ptuning/main.py
@@ -166,8 +166,8 @@ def main():
                 else:
                     prompt = ""
                     history = examples[history_column][i]
-                    for i, (old_query, response) in enumerate(history):
-                        prompt += "[Round {}]\n问：{}\n答：{}\n".format(i, old_query, response)
+                    for turn_idx, (old_query, response) in enumerate(history):
+                        prompt += "[Round {}]\n问：{}\n答：{}\n".format(turn_idx, old_query, response)
                     prompt += "[Round {}]\n问：{}\n答：".format(len(history), query)
                 inputs.append(prompt)
                 targets.append(examples[response_column][i])