Abstract: It was analyzed in this paper the geochemical characteristics and the origin of reservoir bitumen in Wangcun paleo-reservoir in the western Hunan Province,the middle Yangtze region.The reflectance of reservoir bitumen from the Lower Ordovician to the Upper Cambrian Zhuitun Formation ranged from 3.09% to 4.08%.The bitumen was rich in H and C,poor in O,and was highly mature.From the Lower Ordovician to the Upper Cambrian,geochemical characteristics of bitumen were similar,indicating the same source.Oil-source correlation studies with biomarker and carbon isotope showed that the bitumen in the Wangcun paleo-reservoir mainly originated from the Lower Cambrian source rocks.