The People’s Republic of China has taken substantial steps to reform its financial system, especially the banking sector, since 1995. The speed of banking reform has accelerated after China joined the World Trade Organization (WTO) in December 2001. This study examines the impact of recent banking reforms and of WTO accession on the cost efficiency of the Chinese banking sector. We use a non-parametric approach to investigate the efficiency trend and productivity growth of banks in China between 1998 and 2006. We also compare the efficiency and productivity growth of different banking ownership groups prior to and after joining the WTO. We find that, on average, domestic banks outperform their foreign counterparts over the sample period in terms of overall and allocative efficiency, but they fall behind in terms of overall technical efficiency. The comparison of efficiency indexes pre and post WTO accession reveals that the efficiency of domestic banks has declined post accession, while foreign banks have enjoyed an improvement rise in their cost efficiency post WTO accession in 2001.The findings of this study further suggest that the total factor productivity of Chinese banks has weakened over the period under study. However, a pre and post analysis of WTO accession results shows that total factor productivity has improved for both domestic and foreign banks after China joined the WTO, equally owing to efficiency improvement and technological progress