文章基于我国A股上市公司2016-2021年的经验数据，运用Heckman两阶段模型，对环保支出对企业价值的影响进行了实证探究。结果表明：环保支出与企业价值呈显著的U型曲线关系，两者在环保支出水平较低时呈负相关，在环保支出水平达到一定程度后呈正相关。同时，基于企业异质性的研究发现，重污染企业环保支出与企业价值的关系是U型的，而且影响比全样本更为显著；但非重污染企业环保支出与企业价值呈显著的负相关关系。研究为检验中国当前背景下的“波特假说”提供了一定的证据，也为企业投资方向选择和政府环境政策制定提供了实证依据。

Based on the empirical data of A-share listed companies in China from 2016 to 2021, the study found that there is a U-curve relationship between corporate environmental expenditure and corporate value. Heckman two-stage model is used to eliminate the impact of sample selection bias. When environmental expenditure is less，it will reduce the corporate value, but if environmental expenditure reaches and exceeds the “threshold”，corporate value will be improved. At the same time, based on firm heterogeneity, the U-curve relationship is more significant in heavy-polluted industry. While in light-polluted industry, environmental expenditure is negatively correlated with corporate value significantly. The empirical results provide some evidence to test the Porter hypothesis in the current Chinese context, and also provide advice for corporates on strategy choices and for governments on environmental policy formulation.