Abstract: In the fields of mechanical engineering,etc., product design is a central task of mechanical CAD. Its goal is, the advancement of the design of products and the improvement of the properties of products. The key to achieve it is the integration of information and that of functionality of CAD systems. In consequence, a mechanical CAD environment (ICADE) based on engineering database is developed for a kernel module of general mechanical CAD system.In this paper,the integration of information and that of functionality are emphatically discussed,