[Objective] Changes in land use and carbon storage in Maowei Sea of Guangxi Zhuang Autonomous Region were analyzed in order to provide a scientific basis for increasing its carbon sink capacity and improving its ecological value.[Methods] The supervised classification method was used to interpret and extract remote sensing image data for Maowei Sea in 2009, 2015, and 2021. ArcGIS and the InVEST model were used to analyze spatiotemporal changes in land use and carbon storage in Maowei Sea.[Results] ① The land use types in Maowei Sea mainly showed the distribution characteristics of "large settlement, small mixed residence". The areas of cultivated land, shallow sea waters, and fishery breeding areas decreased, and the areas of mangrove wetlands, building land, forest grassland, and silty tidal flats increased from 2009 to 2021. ② Carbon storage initially decreased and then increased over time. Changes in net carbon sequestration and its net present value in Maowei Sea were, respectively, -1.10×10⁵ tons and -1.37×10⁸ yuan, 3.77×10⁴ tons and 4.66×10⁷ yuan, and -7.29×10⁴ tons and -9.01×10⁷ yuan in 2009-2015, 2015-2021 and 2009-2021. ③ The conversion from high carbon sequestration land use types (fishery breeding areas and forest and grasslands) to low carbon sequestration land use types (building land) in Maowei Sea in 2009-2021 caused the largest carbon storage loss, reaching 2.85×10⁵ t. The conversion to fishery breeding areas increased carbon storage by 1.81×10⁵ t.[Conclusion] Accelerating the conversion and upgrading of farming methods, increasing the proliferation of mangrove forests in terrestrial and aquatic forested areas, and accelerating the construction of forest cities will promote carbon sequestration and sustainable development in Maowei Sea.