Abstract: On the basis of analysis on the types and development characteristics of gas reservoirs in Junggar basin, this paper proposes the discount cash flow as the calculating method for the standard of commercial gas flow, makes an analysis of the related influencing factors,and then establishes the standards for commercial gas flow under different techno?economic policies and conditions in Junggar basin. These standards have been applied in the calculation of new incremental proved gas reserves of Xinjiang Oilfield in 2011, with higher adaptability