In microencapsulation by way of simple coacervation by gelatin, some core materials are encapsulated easily, whilst others are difficult to encapsulate or show an encapsulability dependent on the coacervation-inducing agent. The treatment of core materials to improve encapsulability was studied. It was found that core particle encapsulability can be improved by recrystallization from aqueous solution of an ionic polymer. Electrophoresis, microscopical observation and pH dependency of encapsulability of recrystallized cores revealed that the electrostatic attractive force between gelatin molecules in solution and a polymer attached to the core particle cause gelatin adsorption on the core surface to result in a great improvement in encapsulability.