The northern Shaanxi salt basin is located in the east of the Yishan slope in the Ordos Basin.The study indicates that the salt basin was septarated into the two depressions and the one rise, including the east depression, the west depression and the middle rise.The potassium mineralized characters and the value of Br/Cl×103 indicating the tendency of saline reflect the difference of the sediment environment in the east and west salt depressions.The sedimentological analysis of the M65 subsection from the typical drilling well reveals the difference in the change of water depth, the tendency of concentrating, the potassium showing, the thickness of desalination layer, the input of the terrigenous material.Among them, the west salt depression was affected by the sea water greatly; the water was desalination continuously; the mud distribution reflects the low contribution of the terrigenous material.It is bad for the potash depositing and preservation.The east salt depression was affected by the sea water weakly, and has the bad connectivity with the west salt depression, which leads to the closed sediment circumstance in the M65 stage, showing the small thickness and quantity of the desalination interlayer; the water became deep and concentrating continuously; the mud interlayer was rich, reflecting the contribution of the terrigenous material was larger in the east than in the west.The above characters provide the advantageous geochemistry condition and accommodation.It is conducive for the potash depositing and preservation.