diff --git a/common/constants.go b/common/constants.go
index f9595ee0..1ad0770d 100644
--- a/common/constants.go
+++ b/common/constants.go
@@ -51,9 +51,9 @@ var TurnstileSiteKey = ""
 var TurnstileSecretKey = ""
 
 var QuotaForNewUser = 100
-
 var ChannelDisableThreshold = 5.0
 var AutomaticDisableChannelEnabled = false
+var QuotaRemindThreshold = 1000 // TODO: QuotaRemindThreshold
 
 var RootUserEmail = ""
 
diff --git a/model/option.go b/model/option.go
index 5807ff03..14162420 100644
--- a/model/option.go
+++ b/model/option.go
@@ -54,6 +54,7 @@ func InitOptionMap() {
 	common.OptionMap["TurnstileSiteKey"] = ""
 	common.OptionMap["TurnstileSecretKey"] = ""
 	common.OptionMap["QuotaForNewUser"] = strconv.Itoa(common.QuotaForNewUser)
+	common.OptionMap["QuotaRemindThreshold"] = strconv.Itoa(common.QuotaRemindThreshold)
 	common.OptionMap["ModelRatio"] = common.ModelRatio2JSONString()
 	common.OptionMap["TopUpLink"] = common.TopUpLink
 	common.OptionMapRWMutex.Unlock()
@@ -156,6 +157,8 @@ func updateOptionMap(key string, value string) (err error) {
 		common.TurnstileSecretKey = value
 	case "QuotaForNewUser":
 		common.QuotaForNewUser, _ = strconv.Atoi(value)
+	case "QuotaRemindThreshold":
+		common.QuotaRemindThreshold, _ = strconv.Atoi(value)
 	case "ModelRatio":
 		err = common.UpdateModelRatioByJSONString(value)
 	case "TopUpLink":
diff --git a/web/src/components/OtherSetting.js b/web/src/components/OtherSetting.js
index 0700d0b8..1ea5bf8f 100644
--- a/web/src/components/OtherSetting.js
+++ b/web/src/components/OtherSetting.js
@@ -12,7 +12,6 @@ const OtherSetting = () => {
     Logo: '',
     HomePageContent: '',
   });
-  let originInputs = {};
   let [loading, setLoading] = useState(false);
   const [showUpdateModal, setShowUpdateModal] = useState(false);
   const [updateData, setUpdateData] = useState({
@@ -21,7 +20,7 @@ const OtherSetting = () => {
   });
 
   const getOptions = async () => {
-    const res = await API.get('/api/option');
+    const res = await API.get('/api/option/');
     const { success, message, data } = res.data;
     if (success) {
       let newInputs = {};
@@ -31,7 +30,6 @@ const OtherSetting = () => {
         }
       });
       setInputs(newInputs);
-      originInputs = newInputs;
     } else {
       showError(message);
     }
@@ -43,7 +41,7 @@ const OtherSetting = () => {
 
   const updateOption = async (key, value) => {
     setLoading(true);
-    const res = await API.put('/api/option', {
+    const res = await API.put('/api/option/', {
       key,
       value,
     });
diff --git a/web/src/components/SystemSetting.js b/web/src/components/SystemSetting.js
index 405303a9..d71d8815 100644
--- a/web/src/components/SystemSetting.js
+++ b/web/src/components/SystemSetting.js
@@ -27,16 +27,17 @@ const SystemSetting = () => {
     TurnstileSecretKey: '',
     RegisterEnabled: '',
     QuotaForNewUser: 0,
+    QuotaRemindThreshold: 0,
     ModelRatio: '',
     TopUpLink: '',
     AutomaticDisableChannelEnabled: '',
     ChannelDisableThreshold: 0,
   });
-  let originInputs = {};
+  const [originInputs, setOriginInputs] = useState({});
   let [loading, setLoading] = useState(false);
 
   const getOptions = async () => {
-    const res = await API.get('/api/option');
+    const res = await API.get('/api/option/');
     const { success, message, data } = res.data;
     if (success) {
       let newInputs = {};
@@ -44,7 +45,7 @@ const SystemSetting = () => {
         newInputs[item.key] = item.value;
       });
       setInputs(newInputs);
-      originInputs = newInputs;
+      setOriginInputs(newInputs);
     } else {
       showError(message);
     }
@@ -70,7 +71,7 @@ const SystemSetting = () => {
       default:
         break;
     }
-    const res = await API.put('/api/option', {
+    const res = await API.put('/api/option/', {
       key,
       value
     });
@@ -96,6 +97,7 @@ const SystemSetting = () => {
       name === 'TurnstileSiteKey' ||
       name === 'TurnstileSecretKey' ||
       name === 'QuotaForNewUser' ||
+      name === 'QuotaRemindThreshold' ||
       name === 'ModelRatio' ||
       name === 'TopUpLink'
     ) {
@@ -114,6 +116,9 @@ const SystemSetting = () => {
     if (originInputs['QuotaForNewUser'] !== inputs.QuotaForNewUser) {
       await updateOption('QuotaForNewUser', inputs.QuotaForNewUser);
     }
+    if (originInputs['QuotaRemindThreshold'] !== inputs.QuotaRemindThreshold) {
+      await updateOption('QuotaRemindThreshold', inputs.QuotaRemindThreshold);
+    }
     if (originInputs['ModelRatio'] !== inputs.ModelRatio) {
       if (!verifyJSON(inputs.ModelRatio)) {
         showError('模型倍率不是合法的 JSON 字符串');
@@ -287,6 +292,16 @@ const SystemSetting = () => {
               type='link'
               placeholder='例如发卡网站的购买链接'
             />
+            <Form.Input
+              label='额度提醒阈值'
+              name='QuotaRemindThreshold'
+              onChange={handleInputChange}
+              autoComplete='new-password'
+              value={inputs.QuotaRemindThreshold}
+              type='number'
+              min='0'
+              placeholder='低于此额度时将发送邮件提醒用户'
+            />
           </Form.Group>
           <Form.Group widths='equal'>
             <Form.TextArea