The objective of this work is to investigate the effect of oil fraction (9o) on optimal salinity (S*) and minimum water-oil interfacial tension (ymin). The results reveal that S* and ymm are changing upon changing 60. These results are in agreement with that of the column experiments. The formulation optimized at 9o equal to degree of oil saturation present in the column shows highest efficiency for oil recovery. The change of S* with 8o is described through the coefficient of oil fraction (kp), however, this change does not affect the parameters of the correlation between S* and ymm found in our previous study. These findings provide an useful tool for the selection of surfactant formulations for soil remediation.