Abstract: Taking the agro-pastoral transitional zone of Inner Mongolia Autonomous Region, which has the most extrusive landscape differentiation in Northern China, as the object, a landscape spatial differentiation index was established based on the NDVI, integrated index of land use degree, and aridity index, and the characteristics of the landscape spatial differentiation were quantitatively identified by using SOFM network. The study area could be divided into six landscape zones, i.e., forest zone, foreststeppe transitional zone, agro-steppe mixed zone, typical steppe zone, steppe-desert transitional zone, and desert zone. As compared with the traditional schemes of physical geographical regionalization, our landscape regionalization could quickly regionalize the large scale landscape spatial differentiation in a quantitative way, and the regionalization results were basically in accordance with the original landscape characteristics and the landscape spatial differentiation pattern of the study area.