In order to study the relationship between emulsification and enhanced oil recovery（EOR）of surfactant/polymer complex flooding system with different emulsion，the emulsion characteristics of on-site production fluids of Xinjiang oilfield was analyzed，and the displacement efficiency of the surfactant/polymer complex flooding system was tested，and the migration rule of the emulsion and the contribution of emulsification to enhanced oil recovery were determined. The results showed that the low viscosity emulsion exhibited elasticity at low shear rate，and viscosity at high shear rate. The high viscosity emulsion mainly exhibited viscosity at low and high shear rate. The flooding results showed that the emulsion stability was poor at the early stage of emulsification. At the middle stage of emulsification，the concentration of the chemical agent was higher and the particle size of the emulsion changed well，hence，there existed a compensation of emulsification on the viscosity of oil flooding system. At the end of emulsification，the concentration of chemical agent was lower，the emulsion drop was less，and the degree of emulsification was weaker. When the core permeability was less than 100×10-3 μm2，the enhanced oil recovery increased first and then decreased with the increased of the emulsification comprehensive index（ECI），and the optimum ECI was 55%. When the core permeability was more than 100×10-3 μm2，with the increase of ECI，the enhanced oil recovery increased gradually，and the optimum ECI was 88%， and the contribution of emulsification to enhanced oil recovery was 8 percentage points.