diff --git a/web/public/js/components/common/labels.js b/web/public/js/components/common/labels.js
index ef3c8a92..94350e5e 100644
--- a/web/public/js/components/common/labels.js
+++ b/web/public/js/components/common/labels.js
@@ -43,3 +43,8 @@ Vue.component("grey-label", {
 	},
 	template: `<span class="ui label basic tiny" :class="labelColor" style="margin-top: 0.4em; font-size: 0.7em; border: 1px solid #ddd!important; font-weight: normal;"><slot></slot></span>`
 })
+
+// 可选标签
+Vue.component("optional-label", {
+	template: `<em><span class="grey">（可选）</span></em>`
+})
\ No newline at end of file
diff --git a/web/views/@default/clusters/cluster/settings/dns/index.html b/web/views/@default/clusters/cluster/settings/dns/index.html
index baf096c6..12131616 100644
--- a/web/views/@default/clusters/cluster/settings/dns/index.html
+++ b/web/views/@default/clusters/cluster/settings/dns/index.html
@@ -27,7 +27,7 @@
 				</td>
 			</tr>
             <tr>
-                <td>自动设置CNAME记录</td>
+                <td>自动设置CNAME记录<optional-label></optional-label></td>
                 <td>
                     <values-box :values="cnameRecords" name="cnameRecords" placeholder="记录名" ref="cnameRecords"></values-box>
                     <p class="comment">除集群已创建的网站服务之外，自动解析到集群的CNAME记录，比如<code-label @click.prevent="addCnameRecord('@')">@</code-label>、<code-label @click.prevent="addCnameRecord('www')">www</code-label>。</p>