The Ordovician Northern Shaanxi Basin is one of the largest marine saltforming basins found in China up to now. The authors conducted systematic field documentation of the originalstate cores recovered from five wells (Mitan No. 1, Sui No. 1, Jia No. 1, Zizhou No. 1 and Wubao No. 1) completed recently in the sixth submember of the fifth member of the Majiagou Formation in the basin and performed integrated sedimentological, mineralogical and geochemical studies. The results indicate that the evolution of the saltforming brine in this submember has reached the stage of sylvite deposition; especially, the mineralogical and geochemical characteristics of the core from the Sui No. 1 well in the southeastern part of the basin show a better potashbearing manifestation, predicting that the Northern Shaanxi Ordovician Salt Basin has good potash prospects.