Abstract: This paper describes a CIMS-Oriented Engineering Database Management System. The object-oriented notions and methods are introduced to this system. It is established on the basis of RDBMS ORACLE and integrated with the graphical software GKS. As a result, it possesses abilities to support abstract data type, class hierarchy and inheritance between them, complex object management, uniform manipulation for graphical and non-graphical data, version management and long transation processing and diversified interface. The paper lays emphasis on Object-Oriented Engineering Data Model (OEDM), the architecture and the modules of the system and OSQL implementation.