Abstract: In recent years,learned by Fertilization, a large area of farmland soil available K declined very significantly.Planted corn area has reached 772000hm2 of high-yield areas,potassium deficiency has become a major factor in restricting corn yield and quality.So,according to the analysis of potassium literacy maize plants sub-results,the great importance of K fertilizer. Especially the recommendation of the application of potassium chloride.