Based on the surface geological investigation , thin sections study of profile and wells, this paper analyzed the characteristics and the relationship of reservoir bitumen with other minerals in outcrops, drilling cores by microscope, and had an oil to source correlation by geochemical methods. Some conclusions drawn are as follows: ① Two generations reservoir bitumen have been found in the Sinian, but just one generation in the Lower Paleozoic. Reservoir bitumen in the Sinian is very abundant and its distribution is controlled by the unconformity karstification. Paleo oil pool of the Sinian is structural lithological oil pools. Slight porous reservoir (intercrystalline pores and intercrystalline solution pores) occurred in the Paleozoic, which controlled by the burial dissolution and recrystallization, and so on. ② Reservoir bitumen content of the Paleozoic is less and its distribution obviously controlled by lithology. The Paleozoic paleo oil pool is a little lithological oil reservoir. ③ The Sinian paleo oil poos in the Dingshan—Lintanchang structural belt is 8.63×108t, and oil cracking gas is 5348.698×108m3. The Silurian paleo oil pool in Liangcun is 2.62×104t, oil cracking gas is 1.62×107m3. ④ Reservoir bitumen from the Sinian to the Paleozoic is a thermal evolution product. The Sinian and Cambrian reservoir bitumen is from the Cambrian source rocks, and the Silurian bitumen is from oil transformational migration and charging of the Sinian paleo oil pool. ⑤ Overall, reservoir bitumen from the Sinian to Paleozoic formation is closely related to the hydrocarbon generation of source rocks and tectonic evolution. The formation time of the first generation bitumen of the Sinian is Caledonian, and formation time of the second generation bitumen of the Sinian and bitumen is from the Cambrian to Permian, is from high temperature cracking in Indosinian—Yanshanian. The gas from oil cracking is one of the most important gas resources from the Sinian to Lower Paleozoic (including Permian) , and the Ordovician and Silurian has favorable exploration prespective, owing to transformational migration of oil cracking gas in the Sichuan basin, especially in Eastern Sichuan and Eastern Chongqing.