The launch of the pilot policy for emissions trading marks the transformation of environmental regulations in China from government collection of pollution fees to inter enterprise emissions trading,which is a development process from Pigou's dogma to Coase's theorem.This paper first analyzes the emission trading system from an economic perspective,then reviews the research progress of the emission trading system,and puts forward suggestions for improving China's emission trading system.Overall,it is necessary to strengthen information technology support and improve the transparency of the emission trading market;strengthen supervision and law enforcement,further improve the allocation mechanism of emission;strengthen publicity and education to promote the activity of the emission trading market.