Purpose: to reveal the patterns of spatial differentiation of irrigation land use with the help of an integral assessment of geo-irrigation situation and the level of use of the Altai irrigated lands. Materials and methods. The study was conducted by aggregation of the rating of key indicators of agricultural land use with the determination of the Irrigation Land Use Index (ILUI) based on a system approach. The database for calculations was formed on the basis of information from federal and regional institutions of the Russian Federation, the portal of the All-Russian Scientific Research Institute for Irrigation and Farming Water Supply Systems “Rainbow”, as well as administrations and enterprises of the Altai municipal districts. Results. Four types of irrigation land use with ILUI index from 0.640 to 17.373 have been identified, varying in the level of irrigated land use and the degree of favorable combination of geo-irrigation parameters. A comparative analysis of the identified types structure with the specifics of the functioning of the regional system of agricultural land use for 31 districts of the Altai Territory and the Republic of Altai showed that the most favorable geo-irrigation situation and the highest level of irrigated land use (ILUI over 5.600) are typical for suburban areas with potato and vegetable specialization of land use and areas in which high values of livestock are observed in combination with a high moisture deficit during the growing season, and agricultural land use is characterized by a lack of natural fodder land and a high share of fodder crops in the crop acres. Conclusions: aggregation of the ILUI evaluation index with the rating of agricultural land use indicators is an effective tool of strategic decision support for implementation of the regional policy of sustainable intensification of irrigated lands.