Abstract: The existence of cluster invisible contracts control the opportunism behavior occurring in the cooperation of industrial cluster enterprises, and make the knowledge sharing cooperation between cluster enterprises be more stability than the other general enterprises. Due to the industrial cluster invisible contract, the enterprises which betray the original knowledge sharing partners will get punishment. In this paper, based on the cluster invisible contract background, a Hoteling game model is constructed to analyze the mechanism of industrial cluster invisible contract to the partner selection of cluster enterprise knowledge sharing behavior. The model is divided into two stages to explore the cluster enterprise knowledge sharing partner selection in decision-making behavior. Specifically, in the first stage, the cluster enterprises can choose the knowledge sharing partners arbitrary, but in the second stage, without the continuation of the first phase of the choice, the cluster enterprise will receive the punishment of the invisible contract in industrial cluster. The results shown that (1) building a broader knowledge sharing partnership in the early stage is good for the long-term development of enterprise, so for the new enterprises into the cluster, establish quality and extensive network connections should be in the first place; (2)the cluster enterprises always prefer to establish knowledge sharing relations with the enterprises which have the greater cluster power. Therefore, when the cluster enterprises establish a new contact with other nodes, they can give priority to the core enterprises in the cluster, and the local government should also strengthen for the cultivation of cluster core enterprise; (3) the invisible contract constraint is helpful to establish a more stable relationship about knowledge sharing network of industrial cluster, which can improve the knowledge revenue of cluster enterprise, and contribute the benign development of industrial cluster.So in the development of the cluster, the invisible contract of industry cluster should be consoidated and developed. For the specialty of industrial cluster, the influence of cluster invisible contract on cluster enterprise knowledge sharing activities, and beneficial enlightenment is provied for industrial cluster knowledge management practice.

Key words: industrial cluster, knowledge sharing, cooperative partners, Hotelling game