The deferrization mechanism of apoferritin was established, and the spectra variation of apoferritin was compared with that of holoferritin. Sodium hyposulfite is a strong reducing agent, therefore, was applied to deoxidize holoferritin to release iron ion，and connection of iron of buffer was measured by the 2,2-dipyridyl. Apoferritin was detected by ICP-MS. Holoferritin was found to have no absorption compared with apoferritin by UV analysis, and have no fluorescence emission spectra in contrast with apoferritin by fluorescence analysis.