Abstract: Under the background of ecology priority and green development, environmental protection tax makes a profound impact on enterprises’ environmental behavior and economic benefits. This paper studies the mutual effect between environmental protection tax, environmental responsibility and enterprise value with China’s Shanghai and Shenzhen A-share industrial listed companies from 2012 to 2020 as research subjects. The empirical results show that environmental protection tax influences the value of enterprises, which displays an “inverted U-shape” indicating primary promotion and ensuing inhibition. Environmental protection tax reduces the effort that enterprise makes in taking its environmental responsibility, showing a “negative tax effect”. Although environmental responsibility mediates between environmental protection tax and enterprise value, the intermediary role takes the form of masking effect. After heterogeneity analysis, it is found that the environmental protection tax greatly affects the enterprise value in non-state-owned enterprises and heavily polluted ones, but it is not so in state-owned enterprises and non-heavily polluted enterprises. The above results show that further improvement should be made in the environmental protection tax policy to promote enterprises’ environmental responsibility awareness and make the sustainable development possible.