Abstract: OBJECTIVE To prepare amygdalin self-microemulsion and to carry out preliminary quality evaluation. METHODS The best prescription of amygdalin was screened by the determination of equilibrium solubility and drawing of pseudo-ternary phase diagram. The particle size, polydispersity coefficient and stability of amygdalin self-microemulsion were evaluated. RESULTS The optimum formulation of amygdalin self-microemulsion was Peceol/MCT(1︰ 1)-emulsifier OP-1,2- propanediol=45%︰ 40%︰ 15% with drug loading of 6 mg·mL^-1. The average particle size of amygdalin self-microemulsion was (113.3+0.8) nm, and the polydispersity coefficient was (0.171+0.007). The centrifugal stability of amygdalin self-microemulsion was good. CONCLUSION The optimized formulation is stable and feasible, and the prepared amygdalin self-microemulsion has uniform particle size and good stability.