The Dianjiang salt basin, located in the eastern part of Sichuan basin, is one of the most important Triassic salt basins in eastern Sichuan basin. However, the metallogenic condition of marine potash formation has long been in dispute. This paper carried out an analysis for the halite samples from Gaotan well 1 and Changping well 3 in the Changshou area using microscopic observation, scanning electron microscope, X- ray power diffraction and chemical components. The results show that the core samples from Changping well 3 contain high K+ concentration up to 3.82% and a large number of polyhalite and minor amount of sylvinite were found at depth between 2749 meter to 2778 meter in Changping well 3. Br×103/Cl coefficients of the samples from two wells suggest that the brines reached the deposition state of sylvinite. Study of the paleoclimate conditions, materials source and tectonic conditions in the Changshou area shows that this area was characteristic of high paleo- seawater temperature and hot climate during the early Middle Triassic, both of which were beneficial to the formation of potash deposit. The materials of potassic salt were mainly derived from seawater, which provided plentiful sources for potassium ion. There might exist a secondary sag in Baohe village. Good structural condition helped the formation and preservation of potash deposits. Therefore, this area will be the target for exploration of potash deposits.