Abstract: This paper measures the total amount of the carbon sink of mariculture from 2005 to 2012 in China using quality assessment methods,and the results find that the carbon sink capacity of mariculture is huge.The average capacity of the carbon sink of mariculture can reach 1 million tons per year,and the capacity of the carbon sink presents an increasing trend in recent years.On this basis,the reasons of the differences in carbon sink quantities are studied by using the modified Laspeyres index decomposition method,and the results find that the production factor plays a more important role on carbon sink amount increase than the structure factor.Finally,this paper puts forward the suggestions for the improvement of China's mariculture carbon sink capacity.