The invention forms an emulsion by stirring an emulsion material comprising a host material, an organic luminescent material containing no heavy metal element, a surfactant and water under the condition that the host material is melted, and cooling, thereby producing a maximum diameter that is not up to 100 μm luminescent particles. According to this method, it is possible to provide an illuminating particle which exhibits high luminous efficiency in water and is highly safe.本發明係藉由將包含主體材料、不含重金屬元素之有機發光材料、界面活性劑及水之乳液材料於主體材料熔解之條件下進行攪拌而形成乳液，並進行冷卻，而製造最大直徑未達100 μm之發光性粒子。根據該方法，可提供一種於水中表現出較高之發光效率且安全性較高之發光性粒子。
