diff --git a/frontend/module/instance/control.php b/frontend/module/instance/control.php
index 95471eda..bc9be7fe 100644
--- a/frontend/module/instance/control.php
+++ b/frontend/module/instance/control.php
@@ -288,7 +288,7 @@ public function install($appID)
             if(isset($this->config->instance->keepDomainList[$customData->customDomain]) || $this->instance->domainExists($customData->customDomain)) return $this->send(array('result' => 'fail', 'message' => $customData->customDomain . $this->lang->instance->errors->domainExists));
 
             if(!validater::checkLength($customData->customDomain, 20, 2))      return $this->send(array('result' => 'fail', 'message' => $this->lang->instance->errors->domainLength));
-            if(!validater::checkREG($customData->customDomain, '/^[\w\d]+$/')) return $this->send(array('result' => 'fail', 'message' => $this->lang->instance->errors->wrongDomainCharacter));
+            if(!validater::checkREG($customData->customDomain, '/^[[a-z]+\d]+$/')) return $this->send(array('result' => 'fail', 'message' => $this->lang->instance->errors->wrongDomainCharacter));
 
             /* If select the version, replace the latest version of App by selected version. */
             if($customData->version)
diff --git a/frontend/module/instance/lang/zh-cn.php b/frontend/module/instance/lang/zh-cn.php
index 1c651f8b..8bad069a 100644
--- a/frontend/module/instance/lang/zh-cn.php
+++ b/frontend/module/instance/lang/zh-cn.php
@@ -273,7 +273,7 @@
 $lang->instance->errors = new stdclass;
 $lang->instance->errors->domainLength         = '域名长度必须介于2-20字符之间';
 $lang->instance->errors->domainExists         = '域名已被占用，请使用其它域名。';
-$lang->instance->errors->wrongDomainCharacter = '域名只能是英文字母和数字';
+$lang->instance->errors->wrongDomainCharacter = '域名只能是小写英文字母和数字';
 $lang->instance->errors->noAppInfo            = '获取应用数据失败，请稍候重试。';
 $lang->instance->errors->notEnoughResource    = '集群资源不足';
 $lang->instance->errors->notEnoughMemory      = '%s 应用需要 %s 内存，当前可用内存%s ，还需要 %s，请扩充内存资源或卸载其他服务后重试！';