diff --git a/src/providers/anthropic.rs b/src/providers/anthropic.rs
index 59cd021..726503e 100644
--- a/src/providers/anthropic.rs
+++ b/src/providers/anthropic.rs
@@ -196,6 +196,7 @@ struct AnthropicRequest {
     model: String,
     messages: Vec<AnthropicMessage>,
     max_tokens: u32,
+    #[serde(skip_serializing_if = "Option::is_none")]
     temperature: Option<f32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     tools: Option<Vec<AnthropicTool>>,
@@ -630,6 +631,36 @@ mod tests {
         assert!(resp.content.is_empty());
     }
 
+    // ---- AnthropicRequest 序列化：未配置的可选字段不出现在请求体中 ----
+
+    fn make_request(temperature: Option<f32>) -> AnthropicRequest {
+        AnthropicRequest {
+            model: "glm-5".to_string(),
+            messages: vec![AnthropicMessage {
+                role: "user".to_string(),
+                content: vec![serde_json::json!({"type": "text", "text": "hi"})],
+            }],
+            max_tokens: 1024,
+            temperature,
+            tools: None,
+            extra: HashMap::new(),
+        }
+    }
+
+    #[test]
+    fn test_request_omits_temperature_when_none() {
+        let json = serde_json::to_value(make_request(None)).unwrap();
+        let obj = json.as_object().unwrap();
+        assert!(!obj.contains_key("temperature"));
+        assert_eq!(obj.get("max_tokens").and_then(|v| v.as_u64()), Some(1024));
+    }
+
+    #[test]
+    fn test_request_includes_temperature_when_set() {
+        let json = serde_json::to_value(make_request(Some(0.5))).unwrap();
+        assert_eq!(json["temperature"], serde_json::json!(0.5));
+    }
+
     // ---- format_error_chain ----
 
     #[test]
diff --git a/web/src/components/Settings/tabs/ModelsTab.tsx b/web/src/components/Settings/tabs/ModelsTab.tsx
index 0e7254f..30342a0 100644
--- a/web/src/components/Settings/tabs/ModelsTab.tsx
+++ b/web/src/components/Settings/tabs/ModelsTab.tsx
@@ -37,7 +37,7 @@ export function ModelsTab({ config, update }: TabProps) {
             </Field>
             <Field
               label="Temperature"
-              hint="控制回复随机性，0 表示确定性输出，值越大越随机。留空使用模型默认值"
+              hint="控制回复随机性，0 表示确定性输出，值越大越随机。留空则不传该字段，由模型使用其默认值"
             >
               <input
                 type="number"
@@ -52,7 +52,7 @@ export function ModelsTab({ config, update }: TabProps) {
             </Field>
             <Field
               label="Max Tokens"
-              hint="模型单次回复最大生成 token 数，超出会被截断。留空使用模型默认值（如 4096/8192）"
+              hint="模型单次回复最大生成 token 数，超出会被截断。留空则不传该字段（Anthropic 型 provider 会回退为 1024）"
             >
               <input
                 type="number"