[Objective] To determine the spatial and temporal dynamics of soil moisture under different vegetation types in loess hilly area.[Methods] We studied the typical slope which was built in Yangou watershed of Yan'an City, Shaanxi Province in 1997. The soil moisture content was measured using drilling method from April to October in 2009 under seven vegetations(apple orchard, Robinia pseudoacacia forest, Hippophae rhamnoides scrubland, Caragana microphyllas forest, Amorpha fruticosa scrubland, grassland, farmland with Setaria talica) in the middle of each month.[Results] The average soil moisture(0-200 cm) in growing season(April to October) was:A.fruticosa scrubland>grassland>farmland(Setaria talica) >R. pseudoacacia forest >C. microphyllas forest >H. rhamnoides scrubland >apple orchard. Soil moisture under different vegetation types was significantly different in the vertical profile. The soil moisture of A.fruticosa scrubland and R. pseudoacacia forest was generally higher than that of grassland. In 0-40 cm, the soil moisture in H. rhamnoides farmland and apple orchard was lower than that in grassland. In 40-120 cm, soil moisture was highest in grassland and lowest in apple orchard. In 120-200 cm, soil moisture of amorpha shrub and farmland was higher than that of grassland, whereas the soil moisture of bushes trees and apple orchard was relatively lower.[Conclusion] The results revealed that C. microphyllasforest, R. pseudoacacia forest and H. rhamnoides scrubland made greater consumption of deep soil moisture, being harmful to the soil water environment and its sustainable utilization.