Abstract:The legal risk in the process of enterprise patent application has great influence on the enterprise's patent application, even affecting the enterprise's destiny. Combined with the cycle of the patents application, according to the analysis of enterprise patent application of generation and evolution characteristics of risk factors in the process of strength, a system dynamics model with module including the enterprise's own patent strength and the national policy environment, was constructed and simulated by Vensim PLE software. The results is verified by the effectiveness and sensitivity of the simulation model, showing that it can be used to fit the patent legal risk and economic losses of enterprises in the process, can provide a theoretical basis for decision makers to choose strategy and adapt for the different risk environmental.