CO2 geological storage technology (CCS) is currently one of the best international options for achieving large-scale low-cost CO2 emission reduction,and the primary issue of CO2 geological storage is the selection of favorable areas for CO2 storage.In view of the insufficient research on the optimization of the favorable area for CO2 geological storage in the Ordos Basin,this paper mainly optimizes favorable areas suitable for geological storage of carbon dioxide in the Majiagou Formation in the Ordos Basin.Methods: Firstly,we determine the boundary of the CO2 geological storage area in the whole Basin through the study of formation water conditions, basic physical conditions,reservoir conditions,structural conditions and caprock conditions with a help of a large amount of geological,drilling, geophysical and laboratory experimental data.Results: After determining the boundary of the CO2 geological storage area,it can be optimized to carry out CO2 geological sequestration in the areas with favorable reservoir conditions,relatively close to CO2 emission sources,high degree of exploration,appropriate depth of formation and little impact on other mineral development.Conclusions: Combined with the early research,we make a conclusion that ① The areas suitable for geological storage of CO2 in the Ordos Basin are located in the east of the Baiyanjing-Shajingzi fault,the north of the northern margin of the Weibei uplift,the west of the Yellow River fault,and the south of the Yimeng uplift,mainly including Iraq The Majiagou Formation in the Shaanxi Slope and Tianhuan Depression except for the missing area of the central paleo-uplift;②The Wushenqi-Jingbian-Yan’an karst slope area (Ⅰ1) is the best CO2 geological storage in the basin Area;③Yulin-Mizhi karst basin area (Ⅰ2) is a favorable place for geological storage of CO2.