In this paper，the activities of science and technology of large and medium sized high tech enterprises are divided into scientific and technological achievements and scientific and technological achievements into productive forces in two stages.By using the KAO model and under the assumption of variable returns to scale a relational network DEA model，we first selected the date of large and medium sized domestic enterprises，large and medium sized state owned enterprises，large and medium sized Hong Kong，Macao and Taiwan funded enterprises and large and medium sized and large foreign enterprise in 2000，2005 20072011 year respectively；then we calculated and analyzed of all kinds of enterprises technical efficiency，pure technical efficiency and scale efficiency.Our empirical research shows that large and medium state owned enterprises and large and medium sized domestic enterprises performed generally less competitively than large and medium sized Hong Kong，Macao and Taiwan funded enterprises and large and medium sized foreign funded enterprises；we find low transformation of scientific and technological achievements into productivity and the scale of low efficiency are the two largest obstacles restricting the development of large and medium sized state owned enterprises and large and medium sized domestic enterprises.