Objective To preparare the ?-carotene microemulsion (?-cm)from Dunaliella salina and study its stability.Methods The influences of some factors on the stability of ?-cm were studied.These factors included light,temperature,air(oxygen),storing time and so on.Results The appearance,color,Zeta potential,volume-Wt diameter and K_(e) were unchanged,but content of ?-cm was decreased with higher temperature(40℃)or stronger light(4500?500L_(x)).Conclusion The preparation should be stored at low temperature and keep away from light.Under this circumstance,the ?-cm was stable for more than 12 months.