On the basis of present geothermal gradient and vitrinite reflectance in the Ordos basin, present geothermal flux was inversed. According to characteristics of paleo-and present geothermal field of the basin, the infleuntial factors were analysed in statistic way and properties of the main infleuntial factors were pointed out. In accompanying with study of tectono-depositional evolution,maturing history of organic matter in different stages and areas of the basin were analysed.