This paper makes a brief analysis on the importance of R D investment in network security enterprises,and then an empirical study is took to evaluate the efficiency of R D activities in 21 network security listed companies in China,by BCC model and Super-Efficiency model of data envelopment analysis. The results show that less than half companies(in the 21 enterprises selected)of which the overall efficiency can reach DEA valid state in BCC model,and some of the companies which are non-DEA efficiency only caused by invalid scale. Using super-efficiency model can make a comparative analysis of those companies which are DEA efficiency under BCC model. Additionally,This paper makes an improvement analysis of R D activities in network security enterprises,and some relative policy recommendations are made to enhance R D capabilities and to achieve optimal size for network security enterprises.