Comprehensive analysis of the Miocene palaeosol in Qin’an area, Tianshui, Gansu, covering micromorphology, particle size, of CaCO₃ content, Rb/Sr, CIW, magnetic susceptibility and chroma, revealed the palaeosol was more developed than the modern soil in the region, and of the soils, however, the palaeosol in the middle and late period of the early Miocene epoch was relatively lower in development degree. The soil is Cinnamon soil-Carbonating Cinnamon soil formed in humid/semi-humid forest/forest-steppe environment, suggesting that monsoon already appeared in Asia as early as that period, with intensity, though quite weak, still quite stronger than the modern one. The palaeosol of the middle Miocene was stronger in development degree, and is Cinnamon soil to brown soil formed in warm and humid climate, suggesting that the monsoon prevailed in Asia in that period and was much stronger than the modern ones.