Whether ESG practices promote or weaken corporate profitability has always been a controversial topic in the academic com-munity,and solving this problem is of great significance for enterprises to achieve high-quality development.Based on the research sample of China's A-share non-financial listed companies on Shanghai and Shenzhen Stock Exchanges from 2012 to 2021,this paper uses multiple linear regression model to empirically test the relationship between ESG practices,audit assurance and profitability.The study found that ESG practices were significantly positively correlated with profitability;audit assurance opinions play a mediating role between ESG practices and profitability;the effect of ESG practices on profitability is more obvious in private enterprises and enterpri-ses in regions with high environmental regulations,and does not differ due to the degree of marketization in the region where the compa-ny is located.