Loess is one of the most widely distributed sediments in northwestern China. The paleosols with a large amount of geological information can well reflect the paleoenvironment. It has important geologic significance for restoring the paleoenvironment and paleoclimate of the research area. In this paper, the geochemical characteristics and paleoclimate of the Late Devonian paleosol in the Baiyin area in Gansu Province were studied by the methods of field observation, combined with carbonate, constant element and magnetic susceptibility. The results showed that the content of carbonate in paleosols in Dahonggou（DHG）and Ciyao（CY）profiles gradually increased from the top to the bottom. Due to the low solubility of carbonate, it accumulated in the soil, indicating that the climate environment was arid or semi-arid. By analyzing the constant element of DHG and CY profile samples, it was found that the chemical composition was relatively uniform, the Na and Ca values were low with an average value of the paleo-soil chemical weathering index（CIA）of 46.59, which implied a weak chemical weathering intensity and the climate is arid. The change of magnetic susceptibility reflects the change of weathering strength of paleosol. The magnetic susceptibility of DHG profile is significantly higher than that of CY profile, suggesting that the weathering（to form the soil by the wind）of DHG profile is strong, and the CY profile being weak instead. Comprehensive analysis shows that the palaeoclimatic environment in Baiyin area of Gansu Province during a certain period of Late Devonian was mainly arid.