Abstract: This paper uses Stochastic Frontier Analysis(SFA)to provide domestic evidence on cost efficiency of state-owned and joint-stock banks, and evaluate the distribution and evolutionary trend of bank cost-efficiency after China financial reform. Our dataset consists of 168 observations from 14 commercial banks during the period 1999-2010. The results suggest:(1)Sample banks’ overall cost-efficiency keeps changing from improvement to stability trend in the sample period, with no obvious fluctuation. (2)State-owned banks are associated with lower cost-efficiency and inefficiency factors impact much more; joint-stock commercial banks’ cost-efficiency maintains higher level in common and shows the trend of improving. The cost-efficiency gap between state-owned banks and joint-stock banks has expanded overtime.(3)Significant relationship of cost-efficiency with assets scale and equity is not found.(4)Room for improvement exists in cost-efficiency of state-owned banks, and internal governance and operational management reform should be strengthened further more.