his paper summarises the development of the concept of Computer Aided Software Engineering(CASE) from the first generation file based integrated UNIX environment to the repository based CASE environment in the early 1990s around data integration, control integration and presentation integration. So it introduces the integrated model of current CASE environment,the principle of the model with CAIS and PCTE as its integrated kernel and the origin of the repository in the late 1980s. Repository resulted frther developnment of PCTE and in 1988 ECMA presented repository-based Roast Bread caaomplishment integration model which is the basic model in the current research of CASE environment.Then it discribes the concept,principle,accomplishment methods and problems in repository in detail and points out that the repository-based CASE environment will have deeply influence on software development.At last,the state of the art of the research in repository-based CASE environment is briefly introduced.