Virtual enterprise (VE) is a mode of organization and management which do some business through networks. Trust is a key factor that determines the success of VE. Reputation-based trust management is considered as a promising way to solve the problem of security issue in VE. This paper proposes a new trust and reputation model which took such factors as recommended trust, direct reputation and reputation time-attenuation etc. into account. Our simulation shows that this model performs well in different case for calculating trust values, it can predict the future behaviors of entities in order to help the core company find trustworthy partners, it can also prevent some vicious attack, solve the problems of no history peer's trust and strengthen network security and robustness. We hope that this model will help move the agents closer to fulfill its promise in the VE based on ASP platform.