A new method was developed for preparing liposomes using an instananeous vacuum-dried lipid mixture. White lipid powder for preparing liposomes was easily obtained by spraying an organic solution of lipids into a vacuum at a temperature exceeding the boiling point of the organic solvent. The lipid mixture thus obtained could be quite easily hydrated and converted to liposomes possessing excellent trapping efficiency and trapped volume. The liposomes thus obtained was superior to that prepared by the freeze-dry or spray-dry method. The present method showed thus be readily applicable to industrial-scale production of liposomes.