In view of the lack of user behavior in existing network virus propagation models a new network virus propagation model which is coupled with user behavior was proposed.Three important factors of user behaviors are extracted, including the user's security awareness, the user's interest in information and the source of link.The parametric function of the model is constructed.On the basis of this model, the threshold controlling the prevalence of network viruses is given by theoretic analyses.The correctness of the theoretical analysis is verified by numerical simulation results.Monte Carlo method is used to simulate the trend of network virus spreading in the case of strong security awareness and weak security awareness of users.The results show that the maintenance of network security needs not only the support of security countermeasures, but also the management of user behavior.