Water resource is a necessity of life for us. Water pollution is an important restriction factor in the process of China's sustainable development. Water pollutants are mainly from our production and living including industrial waste water, domestic sewage and agricultural waste water. China has reduced discharge of waste water and has strived to protect water environment in recent years, but industrial waste water is still a major source of water pollutants. And with more and more industrial enterprises' establishment and development in China, a large amount of the discharge of industrial waste water can do great damage to the water environment and pose a serious threat to the safety of drinking water because industrial waste water contains large quantities of heavy metal ions. So on the one hand we should know the regional difference of standardized discharge of industrial waste water among these regions including temporal difference in each region and spatial difference in each year, on the other hand we must know whether the regional difference is becoming larger in order to make the relevant policies on water protection. Based on the attainment rate of industrial waste water standardized discharge, this paper examines regional difference of standardized discharge of China's industrial waste water among eight regions through σ convergence and β convergence during the period 1998—2008. The results show that there is no significant σ convergence about regional difference of standardized discharge of industrial waste water in China's eight regions during the same period. From the aspect of the time we can see that the spatial difference is not always becoming small in each year, although the trend is becoming small. As far as the temporal difference of China's eight regions is concerned, the in regional difference Southwest China is the largest among eight regions, while eastern coastal region presents the smallest difference. The model of absolute β convergence and conditional β convergence shows that the overall regional difference of standardized discharge of industrial waste water in China is becoming small, initial conditions in each region are critical factors narrowing the differences, and annual growth rate of industrial value-added plays a role as well. Thus these results could help to provide suggestions to policies making for water protection.