The Paleocene-Eocene oil shales of the Gongjue Formation in the Nangqian Basin, east-central Tibetan Plateau, were investigated for their petroleum potential by analysis of organic matter (OM) type, source, richness, thermal maturity, and depositional environment. According to the T-max and molecular indicators, the samples were found to be thermally immature or at the early stages of maturity. The hydrogen index (HI) values and atomic ratios of carbon, hydrogen and oxygen show that the organic matter of oil shales is primarily of Type I or II. The high share of gammacerane and the low pristane-to-phytane (Pr/ Ph) ratio indicate that the organic matter was deposited in saline paleoenvironmental settings.