Abstract: The paper investigates the effects of governance mechanisms on different dimensions of the quality of knowledge transfer, and the moderating effects of the relationships between boundary spanners. We use regression analysis to test the matched survey data from 225 buyer-supplier dyads in the household appliance industry in China. The results show that both contracts and transaction-specific investments have positive effects on the quality of knowledge transfer. While, there are differences in the relative effectiveness of the two mechanisms. Contracts are more effective in improving the quantity of knowledge transfer, but transaction-specific investments are more effective in improving the credibility of knowledge transfer. Meanwhile, the relationships between boundary spanners reduce the positive effects of contracts on the quality of knowledge transfer, increasing the positive effects of transaction-specific investments on the quality of knowledge transfer. The study provides powerful theoretical implications about how to effectively utilize governance mechanisms to improve the quality of knowledge transfer.