Abstract: Studies visual object oriented modeling and the CASE environment that supports it. In order to guarantee the conformity, integrity and flexible sharing of the information in storage, the paper also studies the data storage mechanism of the CASE environment. Accordingly, it discusses the composing and managing pattern, and then brings forward three feasible repository schemes viz. the file method, database method and the integrated method. On the basis of discussion and comparison of the three schemes, it performs the specific design and implementation of the data structure. In addition, they are applied to the CASE UML platform developed.