The Junggar Basin is characterized by more oil and less gas in exploration practice.No major breakthrough in natural gas exploration has been made since the discovery of the Kelameili Gas Field in 2008.In order to jump out from Kelameili Gas Field and look for a new area for natural gas exploration,this study systematically analyzed the components,carbon isotope and light hydrocarbons of natural gases from Dajing area in the eastern Junggar Basin.A comparative study was also performed with the adjacent areas.On this basis,combined with the simulation of source rocks burial history,and its generation and expulsion history,the natural gas accumulation process is determined.Results show that:(1)The natural gas from the Dajing area is coal-derived gas generated from the Upper Carboniferous Shiqiantan Formation at early gas generation stage.(2)Due to the heterogeneity of organic matters,the calculation error of the equivalent vitrinite reflectance of natural gas in the study area is approximately 0.41%,and its actual maturity should be around 1.05%,which is consistent with its dryness coefficient.(3)The Shiqiantan Formation source rocks in the study area generated low-mature coal-derived gas in the Middle and Late Jurassic,and the gas accumulated in the volcanic reservoirs with good reservoir conditions at the top of the Batamayineishan Formation,forming an self-generation and self-storage volcanic-lithologic gas reservoir.