Abstract: According to the analysis of sedimentary-tectonic evolution and sedimentary filling, the Qamdo basin was a superimposed basin during the Mesozoic, an intracontinental rift basin during the Late Triassic and a intermontane downwarped basin formed by the compression of the eastern and western orogenic belts during the Jurassic. The Basin went through three phases of evolution, including rifting, downwarping and collapse, and experienced a strong transformation during the Himalayan. In the Basin, there are three sets of source rocks including the lagoon mudstone and swamp coal-bearing rock series in the Adula and Duogaila Formations, deep lacustrine mudstone and limestone in the Middle Jurassic Dongdaqiao Formation, and four sets of reservoir rocks including the fluvial clastic rocks in the Jiapila Formation, littoral and delta clastic rocks in the Adula and Duogaila Formations, and grainstones and dolostones in the Bolila Formation. In the light of sedimentary-tectonic evolution and petroleum geology, the zone of Qamdo-Qamdun in Zhag'yab is delineated as the most favourable area for the future oil and gas exploration.