MARGIN: auto 0cm" class=MsoNormal>man’,’serif’" lang=EN-US>The biomarkers from the Middle Jurassic bitumen veins in the Qiangzi-1 well in the Qiangtang Basin, northern Xizang are reported for the first time, including n-alkanes, isoprenoid hydrocarbons, terpane and sterane. The maturity parameters and vitrinite reflectance also show that the organic matter in bitumen veins is now in the mature to overmature stages. The biomarkers in the bitumen veins from the Middle Jurassic Xiali Formation sandstone and mudstone are similar to those from the Buqu Formation carbonate rocks apart from different contents of saturated hydrocarbons and aromatic hydrocarbons.mas-microsoft-com:office:office" />