Natural monopoly regulatory reform has greatly sparked our interest. It is believed that changes of the industry productivity efficiency are an important criterion to evaluate the regulation reform. The purpose of this study is to examine Chinas electric power industry efficiency under regulatory reforms in order to evaluate the reform effect and get some references for the future reform. In our research, we first review Chinas electric power industry regulatory reform path for the past 20 years, and then calculates the T?rnqvist index as the total factor productivity efficiency of Chinas electric power industry in the years of 1993-2008. We find that Chinas electric power industry productivity has greatly increased during the study years, especially after a comprehensive reform of institutions in 2002. TFP improvement is quite obvious. We then use a regression model to test the productivity factors with the perspective of efficiency and total factor productivity, confirming that the regulatory reform of the electric power industry has a significant positive impact on the TFP. So it has been proved that regulatory reform in Chinas electric power industry has promoted the development of the industry; in other words the regulatory effect is positive. Finally, based on the empirical results and the actual fact in China, we have made some suggestions on how the government should regulate the electricity industry more appropriately in the future.