Abstract: The examination of the abundances and types of organic matter and levels of thermal evolution of the oil shales from the Wudaoliang Group in the Zonag Lake area in the Hoh Xil Basin shows that the organic matter is characterized by moderate to high abundances,sapropelic type(I)-humosapropelic type(Ⅱ₁) organic matter and low maturity,indicating potential source rocks.The Hoh Xil Basin was once an enclosed carbonate-dominated salt lake basin in the xerothermic conditions during the Miocene.These enclosed and reduced stillwater conditions may facilitate the accumulation of organic matter and formation of the oil shales in the study area.