Abstract: In order to grasp change regulation of macroscopic algae carbon sink capacity in Dongtou County for years and to predict accurately, the carbon sink capacity of macroscopic algae in Dongtou was primarily estimated based on the major macroscopic algae yield of Laver and Sargassum fusiform from 1991 to 2011, the highest year was in 2004(3650.08 t/a), the lowest year was in 1991(278.08 t/a), the average carbon sink capacity was 1875.33 t/a. ARIMA (0,1,3) model building was based on the carbon sink capacity of macroscopic algae in Dongtou. And the carbon sink capacity was identified, simulated and predicted. The results showed that, the residual error of ARIMA (0,1,3) model were all the white noise series. The carbon sink capacity of Macroscopic algae in Dongtou from 1996 to 2011was tested with this model, the highest relative error was 6.39%, the lowest relative error was 0.75%, all the relative error was below 10%, the fitting effect of the model was obvious. The ARIMA (0,1,3) model was feasible and accurate in a short time. According to the model, the carbon sink capacity of macroscopic algae in Dongtou from 2012 to 2014 would be 3697.21 t, 3570.50 t, 3773.32 t, it showed that the carbon sink capacity of macroscopic algae in the next three years in Dongtou would keep increasing on the whole. Therefore, carbon sink fisheries based on macroscopic algae mariculture had remarkable economic, ecological and social benefits. Construction of the incentive measures and mechanisms of the government, strengthen policy guidance and fishery development model innovation were suggested to promote the healthy development of macroscopic algae breeding carbon sink industry.