This paper proposes a cooperative multi-robot system (CMRS) modeling method called fuzzy timed agent based Petri nets (FTAPN), which has been extended from fuzzy timed object-oriented Petri net (FTOPN). The proposed FTAPN can be used to model and illustrate both the structural and dynamic aspects of CMRS. Supervised learning is supported in FTAPN. As a special type of high-level object, agent is introduced, which is used as a common modeling object in FTAPN models. The proposed FTAPN can not only be used to model CMRS and represent system aging effect, but also be refined into the object-oriented implementation easily. At the same time, it can also be regarded as a conceptual and practical artificial intelligence (AI) tool for multi-agent system (MAS) into the mainstream practice of software development.