To understand the spatial distribution of soil hydrological characteristics along slopes, the method of multi-electrode electrical resistivity tomography (ERT) was used in a study started in early May 2009 on a typical mountain slope in the Xiangshuihe watershed of the Liupan Mountains in Northwest China. The slope is 600 m long and covered with an artificial larch (Larix principis-rupprechtii) plantation. A longitudinal transect line was set up from the top to the foot of the slope and three transect lines at different slope positions to detect horizontal variation of the soil electrical resistivity. Results showed that along the longitudinal line, soil electric resistivity, on the whole, though remaining spatially continuous, varied to some extent. It decreased from the slope top to the mid slope and then restoratively increased on the slope downward. As a result of the uneven distribution of soil characteristics, surface topography and vegetation along slope, the longitudinal variation of soil electrical resistivity was greater than its horizontal variation. The electrical resistivity increased with soil depth as gravel and rock content increased with depth. A close relationship was observed between the soil electrical resistivity and soil porosity as well as the volumetric soil water content. The more close relation with the soil water content suggested that it is feasible to determine the spatial variation of soil characters such as the soil moisture through measuring spatial distribution of soil electric resistivity on slope.