Abstract: In order to investigate the variation of the polarity of oil with different concentrations of surfactant,octanoic acid glyceride(ODO)and olive oil were used as model oils to measure the apparent viscosity at different shear rates,the interfacial tension and the anti-coalescence stability of ODO and olive oil containing different concentrations of Sp80 were analyzed. The results showed that the apparent viscosity of ODO and olive oil increased with the increase of Sp80.When the concentration of Sp 80 was less than 5%,the interfacial tension of ODO-water decreased,and the polarity of ODO increased,while the amount of Sp80 required to balance the interfacial tension of olive oil was less than ODO,and when the concentration of Sp80 was higher than 1%,the polarity and interfacial tension of the olive oil had no significant change. Sp80 could enhance the anti-coalescence stability of ODO and olive oil droplets. However,the concentration of Sp80 higher than 5% promoted the coalescence of olive oil droplets. Sp80 could increase the apparent viscosity of the system,effectively decrease the oil-water interfacial tension,and improve the polarity and anti-coalescence stability of oil droplets.