Abstract: In CIM environment, accessing data with high speed during executing CAD geometric modeling systems, may be achieved by using Working Form, One of the essential demands for CIM information integration is that engineering data management supports the STEP/PDES standard for the exchange of product model data. The engineering data management system EXPDES manages neutral fies Working Forms, and databases, which are described in STEP text. EXPDMS supports EXPRESS data model of STEP directly, and it possesses O-O performance.