Based on Difference-inDifference, this paper evalutes the effect on policy of oil and gas moving from a volume-based to value-based tas system, we find that this reform of tax has caused the energy consumption per unit of output to fall between 7.90 percentage points and 8.55 percentage points, the emissisons of pollution to reduce aboud 1556 tons and revenues of resources tax per capita to increase between 2.74 percentage points and 3.03 percentage points relative to the sample average in the western area, then we re-estimate the same model using FGLS, and conclude the similar results.