Information superhighway and improvement of computing power result in increase of the requirements for distributed multimedia applications. But, developer of applications needs much time and efforts because of the difficulties of development, enhancement and maintenance of distributed applications. To solve this problem, CORBA is used widely. But, the definitions of CORBA services are required for the brief developments of distributed multimedia applications. Especially, collaboration service is required because multiple users use distributed multimedia service. Collaboration service manages user and group information of applications and makes the interoperability between of multi users. In this paper, we designed collaboration service for CORBA based distributed multimedia applications. Collaboration service is able to maintain group information and to present the ability for collaborative works between of multi users. Application developers can develop the applications easily because the ability of collaborative works is offered by collaboration service.