diff --git a/theme/index.js b/theme/index.js
index bcb5f14..15808c9 100644
--- a/theme/index.js
+++ b/theme/index.js
@@ -96,10 +96,16 @@ module.exports = (options, ctx) => {
         chainMarkdown(config) {
             config
                 .plugin('custom-style')
-                .use(require('./plugins/markdown/mdCustomStyle'));
+                .use(require('./plugins/markdown/mdCustomStyle'))
+                .end();
             config
                 .plugin('code-result')
-                .use(require('./plugins/markdown/mdCodeResult'));
+                .use(require('./plugins/markdown/mdCodeResult'))
+                .end();
+            config
+                .plugin('img-alt')
+                .use(require('./plugins/markdown/mdAltImg'))
+                .end();
 
             // plugin
             config.plugin('sup').use(require('markdown-it-sup'));
diff --git a/theme/plugins/markdown/mdAltImg.js b/theme/plugins/markdown/mdAltImg.js
new file mode 100644
index 0000000..23ce85d
--- /dev/null
+++ b/theme/plugins/markdown/mdAltImg.js
@@ -0,0 +1,15 @@
+'use strict';
+
+module.exports = (md) => {
+
+  md.renderer.rules.image = (tokens, idx, options, env, self) => {
+    const token = tokens[idx]
+    const hrefIndex = token.attrIndex('src')
+    if (hrefIndex >= 0) {
+      const alt = token.content || (token.children && token.children[0] && token.children[0].content) || '';
+      token.attrSet('alt', alt);
+    }
+    return self.renderToken(tokens, idx, options)
+  }
+
+}
\ No newline at end of file