Abstract：The coastal area of southern Fujian is one of the areas with the highest level of urbanization in China, with its GDP accounting for 51.64% of Fujian Province. It has become the core area for the construction of the "economic district at the west coast of the Taiwan Strait". A city is an ecosystem centering on the human society as well as a system of the unity of opposites with the urban society (population, labor and intelligence) on the one hand and the urban space (geology, resources and natural environment) on the other. Regional crustal stability is considered an essential condition for urban construction, while water is an indispensable natural resource for urban development. The weathering crust of granite is well developed along the coast of southern Fujian and the engineering-geological problem of the soft soil environment is prominent. The paper focuses on the regional stability of a city, supply-demand balance of urban water resources and engineering geological problems that may be involved during urban construction.