Abstract: It is widely acknowledged that northern arid region is agricultural production base considered as the most promising potential area. Land potential productivity (LPP) as land essential attribute is drawing increasing attention. Based on the climate data from 1967 to 1999, soil physiochemical data and maps, with the support of geographic information system (GIS), LPP was computed according to the factors such as radiation, temperature, precipitation, and soil using mechanism method. The results show that water deficiency is the main limiting factor of climatic potential productivity, because climatic potential productivity becomes one third of light-temperature potential productivity according to water correction coefficient; the distribution characteristic of LPP is influenced by many factors, which is same as distribution characteristic of landform. The value of land potential productivity in the basin valley is the highest, and the value in mountain is the lowest.