Based on samples of 82 supplier teams and under the context of cooperative relationship in supply chain, this paper explores the influence of enterprises monitoring on implementing joint liability governance to supplier cluster. We find out that as enterprises monitoring increases, the positive effect of joint liability among suppliers on their peer monitoring decreases, and the negative effect of peer monitoring among suppliers on their opportunistic behaviors decreases. Meanwhile, it also weakens the indirect inhibiting effect that suppliers joint liability exerts on opportunistic behaviors through peer monitoring. Therefore, when implementing joint liability governance, the enterprise should limit the dependence on its power or position advantage and reduce its monitoring on suppliers for fear that the effect of peer monitoring within the cluster might be counteracted.