Overgrazing accelerates soil and vegetation degradation in rangelands. So, Livestock Population Density-i.e. allocated number of sheep per ha can serve as an index for measuring pressure on range environment. For this purpose, Sadra region has been selected as the study area, where it is located in the upper reaches of Maharlu basin, Fars Province, Southern Iran. This study is to assess livestock pressure on rangeland in the study area, using Geographic Information System (GIS) tools and a model based procedure.