中文摘要：

指出了社会福利应包括经济福利和环境福利.在环境-经济复合系统模型的基础上,建立了外部效应内在化的生产函数和效用函数,通过分析认为企业生产应该将经济效益与环境容量相结合,政府根据环境容量（自净率）来调节污染税,并进行公共投资决策.

英文摘要：

Social welfare should include economic welfare and environmental welfare. Based on environmenteconomy compound model, we establish production function and utility function which internalize external effects. Enterprise＇s production should be related to economic benefit and environmental capacity. Government can regulate pollution taxes according to environmental capacity （self-cleaning ratio） and make public investment policies.