Abstract: The assessment of Mangrove area stability plays an important role in the protection and utilization of mangrove in Maowei Sea , Guangxi. We discussed the effects of global mean sea level rise, crustal rise, tidal flat deposition, tidal flat slope and seawall on mangrove area in Maowei Sea from 2000 to 2100. We established the prediction model of mangrove boundary position, used the prediction model to estimate the elevation data of mangrove boundary in 2100 and located the spatial location of mangrove boundary. After analyzing the mangrove area change, we got the following conclusions. (1) When the global mean sea level rises in a low mode, the mangrove area will increase greatly in the northeast section of Maowei Sea and increase moderately in all of the northwest, southeast and southwest sections. When the global mean sea level rises in a medium mode, the mangrove area will increase greatly in the northeast section, increase slightly in the southeast and southwest sections and be stable in the northwest section. When the global mean sea level rises in a high mode, the mangrove area will decrease greatly in the northwest section, decrease moderately in the northeast section and be stable in the southeast and southwest sections. The reduction of mangrove area in the northwest and northeast sections will reduce the ecological function and resource value of mangroves, which must be paid special attention. (2) The main reason for the decrease of mangrove area in the northwest and northeast parts of the Maowei Sea is the movement of the mangrove seaward boundary towards land caused by the global mean sea level rising in a high pattern. (3) When the global mean sea level rises in a high mode, the seawall should be demolished or retreated appropriately in the northwest and northeast sections to increase the mangrove area on the landward boundary side so as to offset the reduction of mangrove area on the seaward boundary side.