Abstract: Located in the northeastern part of the Gangdise-Nyainqentanglha block,the Biru Basin as a Mesozoic-Cenozoic marine basin in Xizang was grounded on the pre-Sinian metamorphic-crystalline basement and Palaeozoic folded basement,and has witnessed three stages of evolution,including the passive continental marginal basin during the Late Triassic to the Early-Middle Jurassic;the compound back-arc basin during the Middle Jurassic to the Early Cretaceous,and the basin collapse and plateau uplifting during the Middle Cretaceous to the Quaternary.Compared with the representative passive continental marginal basins,the outer continental shelf deposits and continental slope deposits are absent in the Biru Basin.