Hi jun wu ,
my EJB is normal ejb project and it is not of type DC , and i have solved the above issue by creating another folder in the DTR work space, and i was able to move the project to the DTR following the steps mentioned in the link
http://help.sap.com/saphelp_nw70/helpdata/en/c0/0e0540ba5ee569e10000000a155106/content.htm
Regards
Govardan Raj S