This paper analyses the state of art in workflow management system and then presents cooperative workflow management model based on agent (COWBA), which comprises three levels of architecture. The first level is process definition level that defines properties related to activities; The second level is workflow enactment service level that includes instantiated agent, cooperative agent and activity agent; The third level is user interface and invoked application level. Utilizing agent and object-oriented technology, cooperative agent, instantiated agent and activity agent can be built on the basis of object-oriented workflow meta-process model. Therefore, the ability of self-organizing, self-learning and coordinating has been enhanced.