Abstract: Carbon emissions trading system is an important part in the construction of China's ecological civilization system,and it is also an important measure for China to take a lead in the global greenhouse gas emission reduction and build a community with a shared future for mankind in the new era.The process of carbon emissions trading system from scratch,from local decentralized pilot to national centralized legislation constitutes a process of institutional change,to which the theory of institutional change is applicable,explanatory and instructive.The global carbon emission control system is the international institutional background of the domestic carbon emissions trading system,and China's climate diplomacy is the bridge to transform the international carbon emission control system into the domestic system.The domestic carbon emissions trading system includes three aspects:formal rules,informal rules and implementation characteristics.The driving force of China'scarbon emissions trading system comes from the relative price changes with objective basis and subjective influence,and the change process accords with the behavior assumption of the subject,and is affected by lock-in effect and path dependence.When formulating the national carbon emissions trading system,we need to consider the international system to control carbon emissions,the ability to pay in climate diplomacy and the willingness to pay in climate diplomacy.On this basis,we also need to consider the domestic relative price changes,behavior assumptions,lock-in effect,and path dependence and so on.

Key words: carbon emissions, carbon emissions trading, institutional change, relative price, lock-in effect, path dependence