In order to examine the soil water characteristic curve and its influence factors of granite benggang soil,the soil of collapsing gully wall in Anxi County of Fujian Province was taken as the object. Experiment on soil dehumidification was conducted by using the pressure membrane meter, and the soil water characteristic curve of the collapse wall soil was drawn, then the correlation analysis of the curve parameters and the influence factors was carried out. The results showed that the plastic index, clay contents, fractal dimension and roundness were all decreased generally with the increasing vertical depth of the collapsed wall soil. Meanwhile the slope of soil water characteristic curve increased with the increase of vertical depth of the collapsed wall soil, also the water holding capacity, the residual water contents and the VG model parameters a decreased, but the parameters n increased. The residual water contents and parameters (a, n) were all significantly correlated with bulk density and roundness. The residual water contents could be described by bulk density and clay content, the parameter a could be described by bulk density and shape ratio, the parameter n could be described by bulk density and plastic index. The findings can provide reference for the strength test of collapse wall unsaturated >