Abstract: In the context of“dual carbon”goal，China has continuously improved its policies and practices in environmental，social，and corporate governance （ESG），and the impact of ESG information disclosure has attracted wide attention. Based on the data of 4345 A-share listed companies in 2022，this paper uses the propensity score matching（PSM）to study the impact of ESG disclosure behavior on firm value，and explores the mediating effects of market attention，enterprise risk，and financing cost in this impact；it also analyzes the heterogenous effect of ESG disclosure behavior on the enterprise value of different ownership，different scales，different industries，and different regions. The findings reveal that ESG disclosure behavior can significantly enhance enterprise value，and has a greater effect on enterprises with high values. ESG disclosure behavior mainly enhances enterprise value by increasing market attention and reducing enterprise risk. ESG disclosure behavior can more obvious improve the values of non-state-owned enterprises，large enterprises，and enterprises in eastern China，and there is no significant difference in improving the values of enterprises in different industries. The new perspective on the impact of ESG disclosure behavior provides empirical evidence for the impact， mechanism， and heterogeneity of ESG disclosure behavior on firm value. The following policy suggestions are put forward respectively：the government should institutionalize disclosure incentive and differentiate disclosure policies；the enterprise should pay attention to ESG disclosure and optimize asset portfolio；and the investor should fulfill social responsibility and have top-level planning.

Key words: ESG disclosure； firm value； propensity score matching； mechanism inspection； heterogeneity