Abstract:Based on fixed observation on the sloping land in red soil region during 2002~2004,spatio-temporal dynamic change of soil water with various land use types were analyzed.The results showed that the dynamic change of soil water content was affected by precipitation and vegetation primarily,and its seasonal change had three stages: relative stabilization,consumption and supplement stage.Soil water content(0~90 cm) increased with the increase of soil depth.Based on the standard deviation and variation coefficient of soil water content,the soil profile could be divided into three layers generally: the active,the sub-active and the relatively steady layer.The variation coefficients decreased with increasing precipitation and soil depth,but increased with the increasing vegetable roots.The large differences on soil water between deep-root and shallow-root plant plots could be seen in the surface layer(0~30 cm) in rainy year, but under 30 cm depth in average year.The variation ranges of soil water in the deep-root plant plots were wider than those of shallow-root plant plots.