The problem is that JBPM does not recognize your Object as a persistable object. JBPM is capable of persisting Beans by itself, as long as the primary key is a Long or a String, as well as Standard Java Objects. If the Object you are trying to persist does not enter in that category, you will have to : * modify jbpm.variable.types.xml to make JBPM know this Class * Possibly to write a new class implementing org.jbpm.pvm.internal.type.variable (then refer to it in jbpm.variable.types.xml ) * Possibly to write a Converter also. My choice would be to handle all the persistance in the Variable Class. Hope this helps. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4261644#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...