Abstract: Software modeling is a fundamental task of software activities and the core of model driven development process. The "Silver Bullet" type of software modelling is been pursued in software engineering. Based on the analysis of existing software modeling methods, the cooperative-state network was presented to achieve static and dynamic characterization of software system. First, the formal definition, graphical representation and interpretation of related concepts of cooperative-state network were given. Taking a Boiler control software system as example, the model construction algorithm and model reliability analysis were presented in detail. And also, some advantages of cooperativcstate network in software modeling and implementation were described,including easy understanding,one model describing the whole static and dynamic characteristics, executable, analysable, better visualization and consistency, etc.

Key words: Cooperativcstate network, Software modeling, MDD