Nowadays parallel software system is very common and practical. However, it is difficult to test parallel software, because the state space of parallel software is very large. Therefore, a parallel model simplification method based on CPN (Color Petri Net) is proposed. Based on the original CPN, the CPN model for the tested behavior(Tested Behavior of CPN, TBoCPN) is proposed. The target of the test is described as the tested behavior. The relevant behavior is described as the behavior related t