The depth of edge influence

the temporal and spatial variation of soil moisture in different soil layer in Weibei loess plateau were discussed.By using moving split-window method

it was obtained that the depth of edge influence was 16 m from 4 m inside forestland to 12 m outside forestland

the ectone between forestland and grassland was gradual type.The forestland-grassland landscape could be divided into 3 parts;grassland area

ecotone area and forestland area.By traditional analysis methods

it was obtained that soil water in different layers absent or descent with the change of horizontal distance

and that the change of soil water on ecotone area were most significant.The vertical change of soil water in the profile could be divided into four layers in grassland and forestland

and three layers in ecotone area.Based on the seasonal variation of soil moisture

it can be divided into three phase:the soil moisture stocking phase from April to May

the 1ose phase from June to July

the refill phase from August to October.The temporal and spatial variation of soil moisture is mainly affected by the difference of vegetation

soil mechanical composition.