diff --git a/application/default/controllers/ServiceController.php b/application/default/controllers/ServiceController.php
index c818146f..2fed1b05 100644
--- a/application/default/controllers/ServiceController.php
+++ b/application/default/controllers/ServiceController.php
@@ -741,6 +741,21 @@ class ServiceController extends Zend_Controller_Action
 			throw new Exception('发生严重意外！您确认链接正确？');
 		}
 		
+	}
+
+	function mdjsonAction()
+	{
+		$this->_helper->layout->disableLayout();
+		$this->_helper->viewRenderer->setNoRender();
+		$num=(int)$this->_request->getParam('num');
+		$source=$this->_request->getParam('source');
+		if (empty($num)) $num=3;
+		$sql="select m.uuid,m.title,m.id,substring(m.description from 0 for 200) as description from normalmetadata m left join thumbnail t on m.id=t.id where ";
+		if (!empty($source))
+			$sql.=$this->db->quoteInto(" m.uuid in (select d.uuid from datasource d left join source s on d.sourceid=s.id where s.code=?) and ",$source);
+		$sql.=" length(t.data)>2 order by random() limit $num";
+		$rows=$this->db->fetchAll($sql);
+		echo Zend_Json::encode($rows);
 	}	 
 }