As one of the common manganese oxide minerals in the supergene environment, birnessite affects the migration, transformation and environmental fate of sulfur in soil. In this study, the oxidation process of sodium sulfide by birnessite was investigated. The kinds and concentrations of oxidation products of sulfides in solution were determined by spectrophotometry and ion chromatography, and the crystal structures and micro-morphologies of solid oxidation products of sulfides were analyzed by XRD and SEM. It is observed that the main oxidation product of sulfides is elementary substance S, and the S2-oxidation rate follows a pseudo-first-order reaction.