The paper has undertaken field investigation on 216 knowledge workers in knowledgebased industries by structured questionnaire, and varifies that different psychological contract(PC) has different influence on the willingness of tacit knowledge(TK) sharing. The result of analysis shows that the three PC forms proposed by Rousseau are still applicable to study PC of Chinese knowledge workers, balanced PC has significant positive correlation with the willingness of TK sharing, transactional PC has significant negative correlation with the willingness of TK sharing, and relational PC has nonrelation with the willingness of TK sharing.