Abstract: Studies on soil hydraulic characters showed that soil waterholding capacity is very low in the low gneiss mountainous region of Taihang.About one fourth of a year soil water content is below wilt point,and during the growing period of forestry nearly half to one third of the time water is in shortage and irrgation must be applied to the forestry.By application of the ecological engineering to this region,soil water holding capacity was increased by 2.1 time. And plus plastic film cover and straw mulching for reducing soil evaporation the water content of upper layer of the soil was increased significantly.