The miocene sediments in the Linxia Basin are important for understanding the Qinghai-Tibetan Plateau uplift and the east Asian monsoon developments. Hematite and goethite from the Heilinding section in the southern margin of the Linxia Basin were tested. The content of the hematite was high in 11.88.6 Ma, decreasing obviously at 8.6 Ma and kept stable in 8.6～5.0 M. The trend of hematite/goethite ration was similar to hematite content. Such hematite, goethite and hematite/goethite contents in the Heilinding section probably indicate a strong aridification process since 8.6 Ma in central Asia, which was linked to the Qinghai-Tibetan Plateau uplift during this time.