The rim line of present gully can be deemed as a boundary to divide land of stduy area into two sections,namely,the ridge-land above this line,and the gully-land below it.But it is not very often to get the actual proportion because of some subjective reasons and/or some complex objective local characteristics.In this paper,we used aerial photograghs to divide the area into four different regions,selectd typical samples rir-photos,interpreted the rim line of gully,we can get the following conclusions.1)The proportions have some regional differences,but no zonal regularuty in this area.2)This propertions are not only restricted by palaeo-topography,but also impacted by human activities.3)Ridge-land amounts to about 35% in the region where deep-level land slip appears very commonly,45% in rivers source area and 40% in the rest areas.