Abstract: There exist vertically structural sequences of Paleozoic, Mesozoic and Cenozoic in Kongquehe slope area, Tarim basin, horizontally nose-like uplifts of Baliying-Puzhong-Qunke and Longkou-Weima-Kaiping, and effective source rocks of continental Jurassic and marine Cambrian-Ordovician. Paleozoic and Mesozoic reservoir-cap rock assemblages are well developed, with good space-time configuration between trap shaped period and generation or expulsion period of hydrocarbons in source rocks and good preservation nature, which are favorable for forming large scale oil-gas reservoir conditions. Kongque-1 Well, located on Weima No.2 anticline structure in Kongquehe slope, has produce gas flow by drillstem test of Silurian. It is considered from analyses of the gas property and geochemical feature that formation of the gas in this area is of characteristics of multi-source composite and multi-stage continuity, belonging to petroliferous gas formed by sapropelic parent material, and marine sedimentary source rocks of Lower Paleozoic.

Key words: Tarim basin, Kongquehe, oil source bed, gas formation, mechanism