Abstract:This paper presents a profound study of the Computer Supported Cooperative Work (CSCW) and workflow system.Based on the former researches,the paper presents a more useful grid workflow system reference model with a consideration of the properties of grid environment.An analysis is made of the cooperative mechanism based on cooperation context of Grid workflow system and technologies about message middleware.The implementation method of the cooperation mechanism for grid workflow is proposed,and then an application instance is provided to illustrate our approach.