Shidong area locates in the west of the Dishuiquan Sag of the Junggar Basin, adjacent to the Shixi oil field (with 108 t reserves) and the Kelameili gas field(with 1011 m3 reserves). The dry coefficients of natural gas in Shidong area are high, and the carbon isotopes of methane and ethane are heavy, which is different from those in the Shixi oil field and similar with those in the Kelameili gas field. Crude oils from both deep and shallow formations in Shidong area have the same characteristics basically. The studies have indicated that the petroleum in Shidong area comes from the Dishuiquan Sag rather than the Shixi oil field.