Abstract: Junggar Basin is a large composite and superimposed basin, which is developed from the basement of micro- plate after suture and accretion and Paleozoic island-arc belts, controlled by the evolution of paleo-Asian ocean and its peripherial orogenic belt. Since Phanerozoic eon, the basin has undergone five cycles of tectonic evolution, i.e. the extension-subduction cycle of Cambrian-middle Silurian north Junggar ocean, the pull-apart and convergent cycle of late Silurian-early Carboniferous Kelameili limited ocean-basin, fully extinct cycle of late Carboniferous -Triassic paleo-Asian ocean, the intra-continent fault-depression cycle during the period of early Jurassic-Eogene and the strong transpressional and convergent orogenic cycle during the period of Neogene and Quaternary. During the extending period, the stable sequences of original basin often develops better source rock, and in convergent period, the proto-type basin was suffered from reconstruction, and this period becomes the development stage of structural trap or oil/gas accumulation. In addition, after resuming the evolution process of the basin, it is pointed out that the Devonian-Carboniferous will become new target for oil/gas exploration in Junggar Bain in the future