Abstract: How to price resources is an important problem in the grid market. Traditional price policies cant price differently for consumers with different reputation values, thus it has no incentive for users to provide honest services. A differential pricing strategy based on trust group was presented by analyzing the impact of trust relationship between consumer and provider on price strategy. Resource consumers are divided into two categories: nodes in a trust group and nodes out of the trust group. Resource providers charge different types of nodes different prices. Since the differentiation is based on the trust relationship, it encourages nodes to provide trustable information/services. Analysis and simulation results show that the differential pricing strategy can improve the success rate of transactions and reduce the average cost payable by nodes for the services.