Four years experiment was conducted to investigate the influence of fertility on grain yield of maize and its component. The results indicated that the high input of fertilizer significantly enhanced maize yield, four years average annual increased of 6.1%. In the middle semi-humid region of Jilin Province, accumulated temperature and sunshine was not limited factors of corn growth and yield formation. The rainfall was the main factor affecting maize yield. In 2008, rainfall was enough and allocation more reasonable, average yield of the three treatments increased by an average of 22.0% over four years.