Abstract: On basis of the field's late sowing experiment of Keng in the South of Henan,it was found that the growth period shorted 14 days,the filling and maturing period prolonged 8.5 days,the single yield increased by 8.43%,and the quality has been improved.Falling the temperature of the flowering and filling period of Keng will facilitate increasing the rate of seeding and the weight of Kilograin,this is the reason why late sowing can increase production.