Abstract: In view of the current phenomenon of stealth discharge,the illegal discharge of pollutant discharge of enterprises is considered,and the interactional relationship between the pollutant discharge enterprises and local governments under the environmental tax and related implementation regulations is studied from the perspective of organizational behavior and using evolutionary game theory. The chemical oxygen demand of the pollutant discharge enterprises in Anhui province is given as analysis of example. The research shows that:(1)the environmental tax and related implementation regulations can not completely eliminate the illegal discharge behavior of enterprises,but can make the evolution process of pollutant discharge enterprises and local governments converged to a mixed evolutionary stable strategy(0.734 9,0.965 4);(2)the probability of final legal discharge strategy is positively correlated with the volume of stealth discharge,and the small volume of stealth discharge should be seriously supervised;(3)the proportion of stealth discharge has a threshold value,which is the key to promote environmental behavior; limiting the proportion of stealth discharge below 16.7% and then promoting the removal rate of pollutants is an important way to improve the environmental behavior of illegal pollutant discharge enterprises.