Functional relationship exists among carbon and oxygen isotopes of lacustrine deposits, elevation and mean annual temperature in the Tibetan Plateau. Paleo-altimetry was established by statistical analyses on carbon and oxygen isotopes of 35 lacustrine samples from 14 outcrops at different elevations in the southern Tibetan Plateau. Such a paleo-altimetry was used for calculating paleo-annual temperature and paleo-elevation of the Tibetan Plateau based on carbon and oxygen isotopes of lacustrine sediments formed in the Oligocene, Early-Middle Miocene and Pliocene-Early Pleistocene. The results show that most areas of the Tibetan Plateau uplifted to ~4000m, the Wudaoliang Basin and the southern part of Kunlun Mts. to ~3500m and the Qaidam Basin to ~2500m in the Early-Middle Miocene. These data are of significance for better understanding uplifting process and environment change of the Tibetan Plateau.