Abstract: Based on the research results of geographical studies of the Qinghai-Xizang Plateau in the last two decades, the main progress of studies on the paleogeographical evolution, natural envi-ronment and its regional differentiation, as well as environmental problems are dealt with in the present paper. The altitude of the Plateau surface remained generally at a mean elevation of 1000 m asl until the occurence of intense uplifting between the end of Pliocene and beginning of Early Pleistocene. A total uplifting magnitude of 3500 m, with differentiations in space and stages, has been attained over most parts of the Plateau since Quaternary. The intense uplifting of the Pla-teau has given rise to enormous changes of the natural environment since Late Cenozoic, such as the evolution of lakes and drainage systems, the Quaternary glaciation, the paleogeographical evo-lution in the Holocene and the influence of uplifting of the plateau on natural environments and processes. Characterized by the most outstanding features of natural environment the Qinghai-Xizang Plateau differs to a great extent from the Eastern Monsoon Realm and the Northwest Arid Re-alm in China. According to comparative studies of the attitudinal belt, two systems of the stru-cture-type of the attitudinal belt may be identified: the monsoonal and the continental. From a point of view of three dimensional zonation, the spatial differentiations of the Plateau are exp-lained and a tentative scheme of physico-geographical regionalization has been proposed. A number of geo-ecological phenomena, such as the vapour channel, dry valley and the cold-arid core area are discussed in the present paper.

Key words: Qinghai-Xizang Plateau, Paleogeographical evolution, Natural environ-ment, Regional differentiation