In order to examine the mixing degree of loess material, the authors investigated the geochemistry of three last interglacial paleosol (S1) sections from northwest to southeast in the Chinese Loess Plateau using X-ray Fluorescence and Inductive Coupled Plasma Mass Spectrometry methods. The ternary plots of stable elements, Al-Ti-Zr, a robust method to indicate sediment provenance, show a confined cloud in each loess-paleosol section, and the clouds are almost overlapped when they are in the same plot frame. This highly suggested the homogeneity of loess material,and also indicated that the loess parent materials must have been thoroughly recycled before they deposited to the Chinese Loess Plateau. All of them suggest that loess material is a good starting point for estimating the average composition of the UCC.