Abstract: The source rock of Yangye formation in Jianggalesayi structural belt of Tadongnan depression in southeastern Tarim basin is characterized by high organic matter abundance and maturity, being as the major source rock in this area. This paper presents the geochemical analyses of chromatogram and chromatogram?mass spectrum of core samples of four oil?sands and four source?rocks from the Jianggalesayi structural belt and the comprehensive correlation of parameters of sedimentary environment of oils, source rocks and maturity. It is suggested that there is a big difference between the lacustrine mudstone and the coal measure shale in this area as follows: The lacustrine mudstone of Yangye formation is originated from the mixed source of higher plants and lower organisms, the coal measure shales of Yangye and Kangsu formations are dominated by the higher? plants origin; the oil sands from the Aishahantuohai and Qigeleke belong to the same source supply and the source rock is the lacustrine mudstone of Yangye formation. It is inferred that there could be two types of pool?forming models: the one is near?source vertical migration reservoir dominated with the Aishahantuohai oil sand, and the other is the near?source lateral migration one dominated with the Qigeleke oil sand