Based on a summary and analysis of the analytical data of the formation water in 451 wells, the authors studied the characteristics of the salinity and types of the formation water of Maokou Formation in Shunan area. In combination with the drilling, seismic and logging data, this paper has systematically summarized the vertical zonal mode of the paleokarst, elaborated the development features of various karst zones along the profile, and analyzed the storage styles of the formation waters with different chemical properties. The result shows that the salinity of the formation water is on the whole relatively low with a large variation range and that the distribution of the salinity is connected with the potential energy.