Abstract: ‘Han6172’, a main wheat cultivar in Hebei, was used in this experiment in order to provide scientific basis for potassium fertilizer rational use of potash fertilizer in the southern Hebei. The potassium fertilizer was included six fertilizer levels of 0, 37.5, 75, 112.5, 150, 187.5 kg/hm². The results showed that, the potassium fertilizer could significantly increase grain yield of winter wheat, and the yield increased between 3.93%-9.82%. The grain yield of the wheat increased with the increase of potassium fertilizer rate, the best fertilization was 75-112.5 kg/hm², but efficiency decreased when the potassium fertilizer rate was over K₂O 112.5 kg/hm². Considering of higher yield and economic benefits, the treatment with 75 kg/hm² of K₂O application was optimal with total increment of 8.83% of yield and 838.47 yuan/hm² of profit increment and with 7.49 kg yield per kg K₂O.