The Tibetan Plateau isostatically uplifted after contractional shortening and crustal thickening in Paleogene and is dominated by strike-slip and extension in Late Cenozoic. Very vast lakes formed in Early Miocene and Late Pleistocene in central Tibetan Plateau respectively, and large paleo-lakes formed in Pliocene and Early Pleistocene alternatively in northern and eastern Tibetan Plateau. Level of vast lakes had been base surface for incision in Early Miocene from (24.1±0. 6) Ma to (14.5±0.5) Ma, and lakes and top lacustrine deposits of Wudaoliang Group became base surface for erosion and peneplanation since Late Miocene, which formed plantation surface or peneplain of the Tibetan Plateau.