Abstract: A oversized anticline trap exists in deep Carboniferous of Mosowan uplift in Junggar Basin, but to explore deep oil/gas successfully, it is crucial to determine whether volcanic rocks exists in the upper Carboniferous or not. By comparing the features of oil/gas reservoirs in Mosuowan uplift with those in its adjacent region, it is indicated that there are the large difference of magnetic and seismic anomaly between volcanic and sedimentary rocks, but the magnetic anomaly and seismic facies feature of Moshen-1 well on the top of Mosuowan uplift are similar to those in oil/gas field in Shixi uplift, which is approached to the magnetic anomaly of middle-acid volcanic rocks, standing in the transition belt from strong to weak magnetic anomaly. The analysis result of seismic facies shows that the majority of Mosuowan uplift has the feature of strong amplitude reflection, and weak amplitude reflection ismainly distributed in the southeast sag ofMosuowan uplift. By integrating the magnetic anomaly and seismic facies feature, it is inferred that the upper Carboniferous in Mosuowan uplift would have the following lithologic-facies characteristics: middle-acid volcanic rock plus sedimentary rocks are mainly distributed in the central part of the uplift, and middle-basic volcanic rocks are distributed in the southwest and northeast limbs, and sedimentary rock is occurred in the southeast limb (Fang- 2 well area) of the uplift, the central-southern part of Dongdaohaizi sag and Lunan-1 well area. The late reconstruction of Carboniferous volcanic rocks in Mosuowan uplift has four favorable conditions, it is, therefore, inferred that the Carboniferous volcanic reservoirs would be well developed in the uplift.