The dehydration rate plays a central role in determining moisture content of grain at harvest. In this study, we investigated the grain dehydrate rate (GDR) from 35-55 d after pollination and other correlative traits in 428 maize inbred lines at three locations (Yuanyang, Yucheng, Handan) of Henan province. The results presents GDR shows abundant genetic diversity in three locations, which correlates with the moisture content of cob, bract and significantly relates with grain at 35-55 d after pollination,un-relates with plant height, ear height, tasseling branch, tasseling stage, silking stage. However, the correlation between GDR and physiological mature period and bract number is not clear. In 428 maize inbred lines, GDR at 35-55 d after pollination only significantly correlates with that at 35-40 d after pollination (before physiological maturing period), but, no correlates to GDR at 50-55 d after pollination. This indicates that GDR before physiology maturing period influenced remarkably GDR 35-55 d after pollination as comparison with in other stage. By growth period, grain dehydration rate (>1%) and grain moisture content (<25%) at 55 d after pollination, 42 elite inbred lines with different growth period, low grain moisture content and high grain dehydration rate were identified.