Abstract: In order to explore the palaeoenvironmental changes during the late Pleistocene in the Qaidam Basin, Qinghai and provide the basic data for the study of the effects of the Qinghai-Xizang Plateau uplift on the palaeoclimatic changes, the present paper gives a detailed description of the n-alkane distribution and ASM ¹⁴C dating for the sediments from the ZK-1404 well in the Kunteyi area, Qaidam Basin. The n-alkanes in most of the samples from the ZK-1404 well are characterized by high carbon numbers such as nC₂₇, nC₂₉ and nC₃₁, suggesting the odd-carbon advantage. Several samples contain higher relative abundance short-chain n-alkanes (carbon numbers less than nC₂₁), with nC₁₇ and nC₂₀ as the main peaks and without the odd-carbon advantage. Judged from the n-alkane distribution, ASM ¹⁴C dating, regional geology and palaeoenvironmental studies, the late Pleistocene (33600a to 26370a B.P.) palaeoclimatic conditions in the Kunteyi area, Qaidam Basin display the alterative changes of warm, cool and dry palaeoclimatic conditions, and warm, cool, dry and humid palaeoclimatic conditions, which are distinctly different from the modern continental arid desert climatic conditions.