diff --git a/admin/src/views/user/detail.vue b/admin/src/views/user/detail.vue
index 238c5e4c..192e35da 100644
--- a/admin/src/views/user/detail.vue
+++ b/admin/src/views/user/detail.vue
@@ -228,7 +228,7 @@
     <DialogDisableUser ref="disableUser" :reload="fetchPageData" />
     <DialogModComment ref="modComment" />
     <DialogResetPassword ref="resetPassword" />
-    <DialogIncrementDecrement ref="incrementDecrement" :reload="fetchPageData" :title="dialogTitle" />
+    <DialogIncrementDecrement ref="incrementDecrement" :reload="fetchPageData" :title="dialogTitle" :valuePlaceholder="valuePlaceholder" />
 </template>
 
 <script>
@@ -266,7 +266,7 @@ export default {
             baseInfo: {},
             examInfo: null,
             dialogTitle: '',
-            toChangeField: '',
+            valuePlaceholder: '',
         })
         onMounted(() => {
             fetchPageData()
@@ -310,7 +310,11 @@ export default {
         }
         const handleIncrementDecrement = async (field) => {
             state.dialogTitle = 'Change ' + field
-            state.toChangeField = field
+            if (['uploaded', 'downloaded'].includes(field)) {
+                state.valuePlaceholder = 'Unit: GB'
+            } else {
+                state.valuePlaceholder = ''
+            }
             incrementDecrement.value.open(id, field)
         }
         const handleEnableUser = async () => {
diff --git a/admin/src/views/user/dialog-increment-decrement.vue b/admin/src/views/user/dialog-increment-decrement.vue
index 64058fcb..bb79f21a 100644
--- a/admin/src/views/user/dialog-increment-decrement.vue
+++ b/admin/src/views/user/dialog-increment-decrement.vue
@@ -18,7 +18,7 @@
                 </el-radio-group>
             </el-form-item>
             <el-form-item label="Value" prop="value">
-                <el-input v-model="formData.value" type="number" />
+                <el-input v-model="formData.value" type="number" :placeholder="valuePlaceholder" />
             </el-form-item>
             <el-form-item label="Reason" prop="reason">
                 <el-input type="textarea" v-model="formData.reason"></el-input>
@@ -43,7 +43,8 @@ export default {
     name: "DialogIncrementDecrement",
     props: {
         reload: Function,
-        title: String
+        title: String,
+        valuePlaceholder: String
     },
     setup(props, context) {
         const formRef = ref(null)
diff --git a/app/Models/User.php b/app/Models/User.php
index 2d2b00f5..e0a2c780 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -152,7 +152,8 @@ class User extends Authenticatable
     public static $commonFields = [
         'id', 'username', 'email', 'class', 'status', 'added', 'avatar',
         'uploaded', 'downloaded', 'seedbonus', 'seedtime', 'leechtime',
-        'invited_by', 'enabled', 'seed_points', 'last_access', 'invites'
+        'invited_by', 'enabled', 'seed_points', 'last_access', 'invites',
+        'lang',
     ];
 
     public static function getDefaultUserAttributes(): array
diff --git a/app/Repositories/UserRepository.php b/app/Repositories/UserRepository.php
index e0352362..4e64d6ae 100644
--- a/app/Repositories/UserRepository.php
+++ b/app/Repositories/UserRepository.php
@@ -5,9 +5,11 @@ use App\Exceptions\NexusException;
 use App\Http\Resources\ExamUserResource;
 use App\Http\Resources\UserResource;
 use App\Models\ExamUser;
+use App\Models\Message;
 use App\Models\Setting;
 use App\Models\User;
 use App\Models\UserBanLog;
+use Carbon\Carbon;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Support\Facades\DB;
 use Nexus\Database\NexusDB;
@@ -221,30 +223,60 @@ class UserRepository extends BaseRepository
         $sourceField = $fieldMap[$field];
         $targetUser = User::query()->findOrFail($uid, User::$commonFields);
         $old = $targetUser->{$sourceField};
+        $valueAtomic = $value;
+        if (in_array($field, ['uploaded', 'downloaded'])) {
+            //Frontend unit: GB
+            $valueAtomic = $value * 1024 * 1024 * 1024;
+        }
         if ($action == 'Increment') {
-            $new = $old + abs($value);
+            $new = $old + abs($valueAtomic);
         } elseif ($action == 'Decrement') {
-            $new = $old - abs($value);
+            $new = $old - abs($valueAtomic);
         } else {
             throw new \InvalidArgumentException("Invalid action: $action.");
         }
-        $modCommentText = sprintf(
-            "%s - %s change from %s to %s by %s, reason: %s.",
-            date('Y-m-d'), $field, $old, $new, $operator->username, $reason
-        );
+        //for administrator, use english
+        $modCommentText = nexus_trans('message.field_value_change_message_body', [
+            'field' => nexus_trans("user.labels.$sourceField", [], 'en'),
+            'operator' => $operator->username,
+            'old' => $old,
+            'new' => $new,
+            'reason' => $reason,
+        ], 'en');
+        $modCommentText = date('Y-m-d') . " - $modCommentText";
         do_log("user: $uid, $modCommentText");
         $update = [
             $sourceField => $new,
             'modcomment' => NexusDB::raw("if(modcomment = '', '$modCommentText', concat_ws('\n', '$modCommentText', modcomment))"),
         ];
-        $affectedRows = User::query()
-            ->where('id', $uid)
-            ->where($sourceField, $old)
-            ->update($update)
-        ;
-        if ($affectedRows != 1) {
-            throw new \RuntimeException("Change fail, affected rows != 1($affectedRows)");
-        }
+
+        $locale = $targetUser->locale;
+        $fieldLabel = nexus_trans("user.labels.$sourceField", [], $locale);
+        $msg = nexus_trans('message.field_value_change_message_body', [
+            'field' => $fieldLabel,
+            'operator' => $operator->username,
+            'old' => $old,
+            'new' => $new,
+            'reason' => $reason,
+        ], $locale);
+        $message = [
+            'sender' => 0,
+            'receiver' => $targetUser->id,
+            'subject' => nexus_trans("message.field_value_change_message_subject", ['field' =>  $fieldLabel], $locale),
+            'msg' => $msg,
+            'added' => Carbon::now(),
+        ];
+        NexusDB::transaction(function () use ($uid, $sourceField, $old, $new, $update, $message) {
+            $affectedRows = User::query()
+                ->where('id', $uid)
+                ->where($sourceField, $old)
+                ->update($update)
+            ;
+            if ($affectedRows != 1) {
+                throw new \RuntimeException("Change fail, affected rows != 1($affectedRows)");
+            }
+            Message::query()->insert($message);
+        });
         return true;
     }
 
diff --git a/resources/lang/en/message.php b/resources/lang/en/message.php
index a7da7fa6..4d08c542 100644
--- a/resources/lang/en/message.php
+++ b/resources/lang/en/message.php
@@ -7,5 +7,7 @@ return [
     ],
     'show' => [
         'page_title' => 'Message detail',
-    ]
+    ],
+    'field_value_change_message_body' => ':field is changed from :old to :new by :operator. Reason：:reason.',
+    'field_value_change_message_subject' => ':field changed',
 ];
diff --git a/resources/lang/en/user.php b/resources/lang/en/user.php
index c176720e..2dd57159 100644
--- a/resources/lang/en/user.php
+++ b/resources/lang/en/user.php
@@ -7,5 +7,12 @@ return [
         'list' => [
             'page_title' => 'User list'
         ]
-    ]
+    ],
+    'labels' => [
+        'seedbonus' => 'Bonus',
+        'seed_points' => 'Seed points',
+        'uploaded' => 'Uploaded',
+        'downloaded' => 'Downloaded',
+        'invites' => 'Invites',
+    ],
 ];
diff --git a/resources/lang/zh_CN/message.php b/resources/lang/zh_CN/message.php
index 6d5b0957..fdbf49f2 100644
--- a/resources/lang/zh_CN/message.php
+++ b/resources/lang/zh_CN/message.php
@@ -7,5 +7,7 @@ return [
     ],
     'show' => [
         'page_title' => '私信详情',
-    ]
+    ],
+    'field_value_change_message_body' => ':field 被管理员 :operator 从 :old 改为 :new。理由：:reason。',
+    'field_value_change_message_subject' => ':field 改变',
 ];
diff --git a/resources/lang/zh_CN/user.php b/resources/lang/zh_CN/user.php
index 8ba4e6ab..89b84c82 100644
--- a/resources/lang/zh_CN/user.php
+++ b/resources/lang/zh_CN/user.php
@@ -7,5 +7,12 @@ return [
         'list' => [
             'page_title' => '用户列表'
         ]
-    ]
+    ],
+    'labels' => [
+        'seedbonus' => '魔力',
+        'seed_points' => '做种积分',
+        'uploaded' => '上传量',
+        'downloaded' => '下载量',
+        'invites' => '邀请',
+    ],
 ];
diff --git a/resources/lang/zh_TW/message.php b/resources/lang/zh_TW/message.php
index aaba637b..4a03e7ad 100644
--- a/resources/lang/zh_TW/message.php
+++ b/resources/lang/zh_TW/message.php
@@ -7,5 +7,7 @@ return [
     ],
     'show' => [
         'page_title' => '私信詳情',
-    ]
+    ],
+    'field_value_change_message_body' => ':field 被管理員 :operator 從 :old 改為 :new。理由：:reason。',
+    'field_value_change_message_subject' => ':field 改變',
 ];
diff --git a/resources/lang/zh_TW/user.php b/resources/lang/zh_TW/user.php
index 2a7cf9d6..2e799cdb 100644
--- a/resources/lang/zh_TW/user.php
+++ b/resources/lang/zh_TW/user.php
@@ -7,5 +7,12 @@ return [
         'list' => [
             'page_title' => '用戶列表'
         ]
-    ]
+    ],
+    'labels' => [
+        'seedbonus' => '魔力',
+        'seed_points' => '做種積分',
+        'uploaded' => '上傳量',
+        'downloaded' => '下載量',
+        'invites' => '邀請',
+    ],
 ];