Abstract: To decrease the hemolysis side effect of puerarin, the basic formula and preparation of puerarin submicron emulsion were optimized and the physicochemical properties were evaluated. Puerarin submicron emulsions were prepared by phase inversion-ultrasound combining with phospholipids complexes technology. The effects of preparative parameters, such as emulsification time, stirring velocity and ultrasound time, on mean diameter, span of dispersity, entrapment efficiency and overall desirability were investigated. The three dimensional response surface graphs were produced by second-order polynomial and liner equation, which predict the optimal experiment conditions. All response variables were found to be greatly dependent on three independent variables. Second-order polynomial equations were fitter than liner equations for this study. The optimal emulsification time, stirring velocity and ultrasound time was 15 min, 2 000 r·min^-1, 30 min, respectively. The mean diameter, span of dispersity, entrapment efficiency ,drug content and zeta potential of emulsions prepared by the method were 228.23 nm, 0.628 4, 84.32%, 9.98 mg·mL^-1, -29.03 mV, respectively. Puerarin submicron emulsion was prepared by the optimized preparation method. The narrow particle diameter distribution, high envelopment efficacy and good stability were obtained. The physicochemical properties were suitable for the requirement of the intravenous emulsion.