Information technology is one of Chinas pillar industries. In this paper, we use the Malmquist index method in the data envelopment analysis to make a survey of the productive efficiency of Chinas IT industry and its sub industries by using IT listed companies as a subject. On the basis of this, we make an empirical study of main internal influential factors which affect the efficiency of the industry and some core sub industries. The result demonstrates that the total factor productivity of Chinas IT industry characterized by the IT listed companies is on the steady rise while such productivity of sub industry is not so desirable and stable because of the insufficient technological progress. The reason is that the progress of total factor productivity of the IT industry more depends on the size but not on the technology. At the same time, the financial factor exerts a great positive impact on the productivity of information manufacturing enterprises, but not on the that of information service industry.