Objective:To search for the optimum formula for self-emulsifying preparation of Brucea javanica seed oil.Methods: Taking the emulsifying degree,quantity of non-emulsifying oil,and emulsion particle size as parameters,we screened for the optimum proportions of the oil,lipids, and non-ionic surfactant in the recipe formulation through solubility experiment,orthogonal screen and drawing pseudo-three-phase diagram.Results: For the formulation of Brucea javanica seed oil,better emulsifying effect could be obtained using medium chain length fatty acid triglyceride as the lipids and Tween-85 as the non-ionic surfactant,with the emulsion particle diameter being 0.169 2 μm.And the self-emulsifying preparation had satisfactory quality,stability, and reproducibility.Conclusion: The optimum formula for self-emulsification of Brucea javanica seed oil is:Brucea javanica seed oil∶medium chain triglycerides∶Tween-85 being 1∶1∶4.