Based on the three most important characteristics of cooperation in virtual enterprise, namely hierarchical, dynamic and self-organizational, we propose a Hierarchical Cooperative Model (HCM) to describe the whole cooperative relation and cooperative way in virtual enterprise. A four-tuple is used to formally describe a cooperative actor, in which we use limited Markov chain to describe the dynamic trend of cooperation. Finally, we propose a mixed strategy to implement cooperation at collaborative level, which is the second logic level of HCM. HCM can describe the cooperative relation both statically and dynamically and be able to predict the whole cooperation status in virtual enterprise, which is very helpful for system decision making.