Abstract: In the Permian strata in Zhongguai swell in the northwestern margin of Junggar basin, there exists a kind of mixed rocks of magmatic intrusion and eruption formed by multi?period magmatic activities, with an area of several hundred square kilometers, in which the associated volcanic overflow facies are proved to be good oil?gas reservoirs for high?yield oil?gas flow found in the andesite strata of such a facies on the top of Jiamuhe formation at present. And it is suggested that the favorable locations for oil?gas migration and accumulation are in the fault structures formed by magmatic intrusions and the volcanic channels and overflow facies bodies caused by volcanic eruptions.Hence, the detailed description of the magmatic activity stage and its associated faulting, volcanic eruption facies is of significance for both the analysis of oil and gas accumulation and the prediction of favorable reservoir distribution