Provided are perovskite nanocrystalline particle and an optoelectronic device using the same. The perovskite nanocrystalline particle may include a perovskite nanocrystalline structure while being dispersible in an organic solvent. Accordingly, the perovskite nanocrystalline particle in accordance with the present invention has therein a perovskite nanocrystal having a crystalline structure in which FCC and BCC are combined; can form a lamellar structure in which an organic (or A site) plane and an inorganic plane are alternately stacked; and can show high color purity since excitons are confined to the inorganic plane.