Abstract: Experiments were conducted on plasticfilm and straw dual-mulching in dry land maize fields with plastic film mulch on ridges and different amount wheat straw mulch in channels.The results show that soil water content increases with increased amount of straw mulch.Soil water content within 0～100cm depth averagely increases by 146.2mm under treatments of 5250kg/hm² and 9750kg/hm² straw mulch during the entire growth period of the crop.Water use efficiency of maize with plastic film and straw dual-mulching increases by 16.67%～28.65%,precipitation retention efficiency increases by 12.39%～18.29%,and maize yield increases by 12.10%～18.15%,in comparison with only plastic film mulch on ridges.