Abstract: In this paper, system architectures, design methodologies and modelling techniques of information systems are described in a systematic way, with adequate considerations given to both conceptual abstraction and practice. The paper consists of six chapters: 1. an introduction; 2. the architectures of information systems; 3. system planning method; 4. a practice oriented method for system analysis and system design; 5. the automatic tools; 6. modelling techniques.In addition, some revisions have been made for many different arguments and technical terms which can be found in information systems