Hi, Q1: for each child, you have to do this: ParentBean parent = ...; | ChildBean child1 = ...; | ==> parent.getChilds().add (child1); | child1.setParent(parent); | Otherwise, the relation will not be saved, but there will be no error message. Q2: I don't know what is happening if you call "setChilds" before loading them, but I would expect strange side effects at least when the collection is under EntityManager control (inside a session bean method/transaction). So better manipulate the collection returned by "getChilds" and add/remove items. I will give this a try in the next few days and update my Wiki if I find a "No go". Q3: Did you activate SQL query logging in your persistence.xml? <?xml version="1.0" encoding="UTF-8"?> | <persistence xmlns="http://java.sun.com/xml/ns/persistence" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" | version="1.0"> | <persistence-unit name=".."> | ... | <properties> | ... | ===> <property name="hibernate.show_sql" value="true"></property> | </properties> | </persistence-unit> | </persistence> | But I am not sure how the childs are loaded. I will take a look at the JBoss console when I near a computer with JBoss ;-) Best regards Wolfgang View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4242128#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...