Abstract：The paper mainly discusses the conditions of occurrence of geothermal water and conceptual model of geothermal reservoir structure in the Nanmenxia-Taizi area, Huzhu County, on the northwestern margin of the Xining basin．The conceptual model of the geothermal reservoir proposed in the paper is as follows：stratigraphic control on the geothermal reservoir-lateral runoff recharge of groundwater-terretrial heat supply-terretrial heat conduction along the deep fault-heat storage in low-thermal conductivity rocks. On that basis, it is concluded that: this geothermal reservoir occurs in marble of the the Neoproterozoic Kesur Formation and sandy conglomerate of the Lower Cretaceous Minhe Formation, lies on a slope zone between the Laoyeshan uplift and Shuangshu depression, shows a geological structure of an “uplift in a depression”, and has good geothermal-geological conditions and certain prospects of geothermal resource exploitation and utilization.