"Grid.Qian" wrote : why do you add the yyy.jar to ear directly? which server do you want to deploy the ear to? jboss server? | If you want to deploy the ear to jboss server, I think ,when you create the web projects for client and server, you should select jboss server for these projects and add the yyy.jar to these project. Because your projects have jboss runtime, system do not import jboss runtime again when you import yyy.jar to these projects. And by this way, the yyy.jar will be added to ear automatically. Yes, JBoss Server 4.2.3. I test and you are right, I can add yyy.jar to dependencies of ejb-module which is in ear. But I dont know why it sometimes doest work and sometime work when I tested. Thanks. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4207073#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...