Abstract: Urban and rural construction land is one of the important land use types. Setting bearing capacity of urban and rural construction land, i.e. bearing scope and border is significant for guiding land development. Based on ecological suitability, five types of ecological security elements, including terrain conditions, geological conditions, soil conditions, land biodiversity conservation and water ecological protection, were selected as the ecological constraints for the spatial expansion of urban and rural construction land, and then the integrative ecological suitability and bearing capacity of urban and rural construction land in the coastal areas of Jiangsu Province was evaluated using the GIS spatial analysis tools based on the principle of buckets effect. The spatial distribution of ecological suitability and bearing patterns was mapped, the bearing thresholds were set, and the abundance of bearing capacity in each county and city was counted. According to current distribution of bearing capacity of construction land, the match between bearing capacity and current construction land was evaluated, and bearing potentiality was accounted. The results showed that the ratio of the area of construction land with carrying capacity to the total land area was 29.53% in the case of no harm to ecological security in the coastal areas of Jiangsu Province, however, the area percent of current urban and rural construction land was 15.16%, so there was still 14.37% bearing space of current urban and rural construction land. The ratios of the area urban and rural construction land with carrying capacity to the total land area were 32.12%, 25.28% and 35.41% in Nantong city, Yancheng city and Lianyungang city, respectively. Their area percents of current urban and rural construction land were 16.82%, 12.69% and 18.34%, respectively, so there were still big bearing space of urban and rural construction land for these cities. According to the spatial pattern of ecological suitability in the coastal areas of Jiangsu Province, the seven counties (or cities or districts) including Rugao City, Chongchuan District, Gangzha District, Nantong Economic and Technological Development District, Tinghu District, Xinpu District and Lianyun District have abundant resource for urban and rural construction land, then the nine counties (or cities or districts) including the Qidong City, Hai’an County, Tongzhou District, Funing County, Yandu District, Ganyu County, Donghai County, Guanyun County and Haizhou District are moderate in urban and rural construction land resource, and the left nine counties (or cities or districts) including Haimen City, Rudong County, Dongtai City, Dafeng City, Jianhu County, Sheyang County, Binhai County, Xiangshui County and Guannan County lack of urban and rural construction land resource. The results will benefit to the spatial optimization allocation of the urban and rural construction land and differentiated management.