Writers accounted the pollen species in the 15 cores of Lake Gasikule, Dalangtan, Chahansilatu, Kunteyi, Mahai, Yiliping, and Dabuxun Lake,Senie Lake, Taijinaier Lake (three lakes area) in the Qaidam Basin. Artemisia and Chenopodiaceae pollen content and the ratio (A/C) have been analyzed. And the palaeoclimatic change have been reconstructed in this basin since Late Pliocene based on analysesing the modern ecological environment characteristics about the A/C ratio. It was shown that the palaeoclimate was dry all through the late Pliocene to present but with a great dry—wet oscillation. This character was much obvious from middle Pleistocene. The spatial variation of dry and wet condition changed distinctively in this basin. It was more wet in the eastern part than to the western part. This spatial change characteristic had formed from early Pleistocene or earlier. As the climatic environment of dry and cold to warm and wet in Qaidam Basin has been controlled by the winter monsoon, southeast and southwest monsoon, and influenced by the Qinghai—Xizang(Tibet) Plateau and high mountain around the basin, the dry and wet climate condition has a great difference in the Qaidam basin.