diff --git a/web/src/i18n/en.ts b/web/src/i18n/en.ts
index b0f70d4d..733fa8dc 100644
--- a/web/src/i18n/en.ts
+++ b/web/src/i18n/en.ts
@@ -456,6 +456,7 @@ export const en = {
       logoTip: `Supported image formats: JPG, PNG \n Suggested size: square ratio \n Maximum size: ≤ 2MB`,
       imageSquareRequired: 'Please upload a square image',
       nameInvalid: 'Name cannot start or end with a space',
+      notAllSpaces: 'Cannot be all spaces',
     },
     model: {
       searchPlaceholder: 'search model…',
diff --git a/web/src/i18n/zh.ts b/web/src/i18n/zh.ts
index f04ef4b1..538579f7 100644
--- a/web/src/i18n/zh.ts
+++ b/web/src/i18n/zh.ts
@@ -1036,6 +1036,7 @@ export const zh = {
       logoTip: `支持图片格式（JPG、PNG）\n 尺寸：正方形比例 \n 文件大小限制：≤ 2MB`,
       imageSquareRequired: '请上传正方形比例图片',
       nameInvalid: '不能是空格开头或结尾',
+      notAllSpaces: '不能是纯空格',
     },
     model: {
       searchPlaceholder: '搜索模型…',
diff --git a/web/src/views/Ontology/components/OntologyClassExtractModal.tsx b/web/src/views/Ontology/components/OntologyClassExtractModal.tsx
index 2fd305c6..8d3e1a91 100644
--- a/web/src/views/Ontology/components/OntologyClassExtractModal.tsx
+++ b/web/src/views/Ontology/components/OntologyClassExtractModal.tsx
@@ -185,6 +185,7 @@ const OntologyClassExtractModal = forwardRef<OntologyClassExtractModalRef, Ontol
           rules={[
             { required: true, message: t('common.pleaseEnter') },
             { max: 2000 },
+            { pattern: /^(?!\s*$).+$/, message: t('common.notAllSpaces') },
           ]}
         >
           <Input.TextArea placeholder={t('ontology.scenarioPlaceholder')} />