Phytochemicals self-stabilized Pickering emulsion is expected to be a highly desirable oral self-delivery system. In this study, ursolic acid (UA), a representative pentacyclic triterpene, was reported for the first time that can be formed self-stabilized Pickering emulsion. That is, it is experimentally and theoretically proved that water-in-oil Pickering emulsion could be stabilized solely by UA. First, the morphology, wettability and interfacial properties of the UA particles were characterized. Then, the influence of variation with UA parti...