Abstract: Sannan-Dishuiquan sag in Junggar hasin has heen ocurred in continental depressed and sedimentary stalus in Carboniferous period. The seismie geologic interpretation shows thal upper voleanics sequence. sedimenlary rock and lower volranics sequenee ar developed in Upper Carboniferous in this area. And god! soure rork developed in the sedimentary rock ('onstituters the major gas sourve rocks of Upper Carloniferous gas reservoir in this area together with Dishuiquan source rock of Iower Carboniferuus. 'This paper presrents the studies of the Carboniferous ocurrence. source-reservoir-cap rock conditions of gas rservoir. resoure amnou ssessent and petroleum accunulation model. It is indiraterd that the upper and lower sequencrs of voleanir rocks in the slusdied arera are all gonxd oil-gas reservoirs. The Carboniferous voleanic rourks in Sannan-Dishuiquan sag and is adjacent areas are of gond prsperts for petroleum exploration. with massive gas resourees. being as favorable largets for gas exploration in Junggar basin.

Key words: Junggar basin, Carboniferous, stratum, volcanic rock, natural gas, petroleum accumulation model