Based on relational exchange theory and transaction cost theory, a conceptual model for the relationships among trust, relationship commitment, knowledge trading and cooperative performance is proposed and empirically tested using the data collected from 256 Chinese manufacturing enterprises in supply chain with the structural equation model. The results show that there are significant and positive impacts of trust on relationship commitment, explicit knowledge trading, tacit knowledge trading and cooperative performance. Although relationship commitment has significant and positive impacts on tacit knowledge trading and cooperative performance, it does not impact explicit knowledge trading significantly. Finally, it is also proved that knowledge trading has significant and positive impact on cooperative performance.