Abstract: Technical and economic assessment is a significant approach in measuring the rationality of environmental policy and an instructive tool in formulating practical policy, getting more and more attention by both domestic and international environmental management departments. As one of the few countries where technical and economic assessment of environmental policy was early developed, US has formed a sophisticated evaluation system and provided a well demonstration. The contents of technical and economic assessment of US Clean Water Act were outlined, and its assessment procedure of cost-benefit analysis analyzed. Since China is still relatively new to technical and economic assessment of environmental policy, on the base of learning from the US experience in technical and economic assessment, some recommendations for China’s environmental policy assessment were presented, in order to help improve its methodological system and guide future assessment.