Cenozoic volcanic rocks are widespread over the Qinghai—Tibet Platea u. Vo lcanic eruptions ran through nearly the entire Tertiary and Early Quaternary in age. T h ere is a good coupling relationship between the volcanic activity and lithospher e te ctonic evolution and uplifting process of the Plateau. Differences in the geoche mistry and sources of the volcanic rocks before and after the uplift of the plateau reflected different characteristics of the deep geological events. Vo lcanic activity and plateau uplifting show features multistage evolution and non homogeneith. From the available data it may be inferred that the plateau came up to 4000～ 4500 m at end of the Pliocene. A violent uplift of the plateau since the Pleisto cene was mainly reflected in tectonic mobilization around the plateau. The uplif ting of the plateau is a composion result the manifold factors.