Abstract: According to the characteristics and requirements of data management in cooperative plant design system（CPDS）,C/S mode-based CPDS’s three-layer architecture is presented.A dynamic model of data management is proposed.Major methods for data management are described in detail,such as presentation method of data and topology relationship,version control of design data,data access control,et al. These are all applied to the prototype of CPDS,and the basic data management problems in CPDS are well resolved.