The north slope area of the Mount Qomolangma being a main component of Tethyan Ocean belongs to Himalayan orogen intermediate on the junction between the northern India plate and Yarlung Zangbo river suture belt. There developed basic unharmed marine strata being about 14 000 m in thickness during about 50 million years from the Ordovician to the Paleogene. It is a good area for studying the formation and evolution of the Tethyan Ocean.The Phanerozoic strata in the north slope area of the Mount Qomolangma are made up of three sedimentary facies sets and 15 sedimentary facies and many subfacies. Based on the characteristics of the basin stratigraphic sequences，the depositional systems and the sedimentary facies，the sedimentarytectonic evolution of the basin in Phanerozoic may be subdivided into six stages for the north slope area of the Mount Qomolangma，Tibet.(1)the steady epicontinental sea stage from Ordovician to Devonian；(2)the continental rifting basin stage from Carboniferous to Permian；(3)the passive continental margin stage from Triassic to Jurassic；(4)the early foreland flysch basin development stage in the EarlyMiddle Cretaceous；(5)the late foreland molasse basin development stage from the Late Cretaceous to the Paleocene；(6)the orogenic uplifting stage from the Paleogene to the Quaternary.
