Abstract: This article makes use of the marginal emission reduction cost curve to analyze the logic of international carbon emissions trading theory and predict the results of free trading among Annex B countries. Then it constructs a theoretical model of deadweight loss and import cost saving to analyze the monopsony effect in the international carbon emission trading market. It is confirmed that the import countries of carbon emission right can reduce the total cost of the reduction obligation by setting up the highest import proportion, increase the net earnings of international carbon emission trading, and keep the import proportion with minimum total cost. The developing countries should strengthen cooperation and carbon resource management, strive for the right to speak in international carbon emission trading and negotiations, carry out the innovation of the related property rights system as soon as possible, and establish domestic market trading mechanism.

Key words: international carbon emission trading; monopsony effect; deadweight loss; import cost saving