Employees are the most vital resource of enterprises. Employee＇s voluntary turnover always causes unnecessary damage to enterprise. This paper reviews the studies about employee turnover, then give a process model of employee turnover behavior. The value of qualitative simulation and Kuipers＇ s QSIM is absorbed. Simulation rules are devised by common knowledge and expert knowledge. A program is devised with VB, simulating results accord with the reality. This indicates the method can be used as a virtual experiment tool for the study of employee turnover