Abstract. The emerging multimedia information (such as video, image, voice, graphics) services have imposed many new requirements and research considerations on the design of database management systems (DBMSs). Conventionally, a multimedia DBMS is designed by developing a multimedia presentation layer on top of a pre-existing object-oriented DBMS (which can be truly object-oriented or relational-based), such that the core of the DBMS was developed earlier independent of the design of the multimedia presentation layer. Due to the fact that multimedia capabilities are not actually embedded in the DBMSs, such systems tend to provide only a rather limited set of functionalities in multimedia and are not satisfactory in supporting multimedia applications. This paper describes some key features of a multimedia object-oriented DBMS that is currently being developed. In this system the DBMS is carefully redesigned to provide special multimedia capabilities, such that the mismatch between the DBMS and the multimedia application layer can be eliminated. In particular, this paper will focus on unique multimedia capabilities including multimedia object modeling, video data management, and distributed collaboration.