diff --git a/src/agentscope/models/litellm_model.py b/src/agentscope/models/litellm_model.py
index 242830a38..7a9309c07 100644
--- a/src/agentscope/models/litellm_model.py
+++ b/src/agentscope/models/litellm_model.py
@@ -236,20 +236,18 @@ def format(
                 )
 
         if len(dialogue) != 0:
+            dialogue_history = "\n".join(dialogue)
+
             system_content_template.extend(
-                ["## Dialogue History", "{dialogue_history}"],
+                ["## Dialogue History", dialogue_history],
             )
 
-        dialogue_history = "\n".join(dialogue)
-
-        system_content_template = "\n".join(system_content_template)
+        system_content = "\n".join(system_content_template)
 
         messages = [
             {
                 "role": "user",
-                "content": system_content_template.format(
-                    dialogue_history=dialogue_history,
-                ),
+                "content": system_content,
             },
         ]
 
diff --git a/src/agentscope/models/ollama_model.py b/src/agentscope/models/ollama_model.py
index 1c38d3b8b..b4157c586 100644
--- a/src/agentscope/models/ollama_model.py
+++ b/src/agentscope/models/ollama_model.py
@@ -256,19 +256,17 @@ def format(
                 images.append(unit.url)
 
         if len(dialogue) != 0:
+            dialogue_history = "\n".join(dialogue)
+
             system_content_template.extend(
-                ["## Dialogue History", "{dialogue_history}"],
+                ["## Dialogue History", dialogue_history],
             )
 
-        dialogue_history = "\n".join(dialogue)
-
-        system_content_template = "\n".join(system_content_template)
+        system_content = "\n".join(system_content_template)
 
         system_message = {
             "role": "system",
-            "content": system_content_template.format(
-                dialogue_history=dialogue_history,
-            ),
+            "content": system_content,
         }
 
         if len(images) != 0: