As more and more people enter into the virtual world based on the internet, reputation has become the key to punish the bad behaviors of people and encourage the good behaviors of them. How to evaluate effectively the reputation of the participators is the urgent problem which should be solved. The paper provides a combined reputation model TRUST for distributed environment. This model, according to the characteristics of internet, is based on the direct and indirect experience of service consumer to the service provider. It combines the merits of centralized evaluation and distributed evaluation through binding the centralized reputation and distributed reputation mechanism. Centralized reputation mechanism is used in communities; distributed reputation mechanism is used among communities. Simulating experiments prove this model can give service consumer more profit, thus adapting to the distributed system circumstance better.