Monto-Carlo method is widely used for project risk analysis. Evaluating the risk in HR (Human Resources) investment project, which is of hi-investment and hi-return, by Monto-carlo method is a new attempt. In this paper, by taking cost, profit and risk in the HR investment as index, emulation model of HR investment and index function of risk evaluation were established. Simulation about the whole investment course was done by computer program using Monto-Carlo method. Case study of HR investment risk evaluation was done later using concrete data.