Oil inclusions are the direct indicator of hydrocarbon migration and accumulation, so the GOI (Grain with Oil Inclusion) technique was developed to identify oil site by Eadington et al. (1996). Our researches indicate that the classical GOI threshold, 5% for hydrocarbon accumulation, is not suitable for every petroliferous basin, and the GOI range, 1%-5% for hydrocarbon migration should be changed correspondingly. The statistical and analytical results of GOI values in three basins of China suggest that the GOI thresholds are all less than the classical threshold. Therefore, there should be different thresholds for hydrocarbon migration and accumulation in different geological setting.