Five typical wells with different oil and gas shows were selected for GOI (Grains containing/with oil inclusions) analyses in the Mosuowan area, central Junggar Basin. Analytical results from 48 reservoir samples indicate that the intensity of petroleum charging decides GOI composition. However, due to complex petroleum charge histories in superimposed basins, it is suggested that we should not simply use GOI to define petroleum migrationalong previous threshold line as 1% or 5%. The right way must be based on geological background, to firstly discuss the origin of GOI data and then try to apply them in mapping hydrocarbon charge history. In this paper, a case study in the Mosuowan area implies that GOI can be used quantitatively in the research of petroleum migrationin structurally complex basins.