Abstract: Considering the natural resources consumption and pollutants reduction in the production process as environmental pressures, and utilizing DEA-window analysis to construct pressure generating technology frontier(PGT),this paper measured China's 30 provinces' eco-efficiency over the period 2005-2012 based on provincial panel data from 2003-2012,on basis of which regional differences and evolution trend were analyzed. In order to find out the major constraints of China's each province, aggregated eco-efficiency was decomposed into group eco-efficiency and managerial eco-efficiency. Finally,convergence and Absolute convergence were used to test the existence of convergence in overall China and three major regions. Empirical results were as follows:the overall China's eco-efficiency was still low; regional differences were remarkable among three major regions and had great potential of resource saving and pollution reduction; the major constraints of eco-efficiency were different in different provinces, and the eco-efficiency gaps among provinces from overall China and three major regions all had the tendency of getting larger in the future.