The corrosion behavior of sintered NdFeB in nitric acid hydrochloric acid,vitriol,phosphate and oxalic acid was studied.Potentiodynamic polarization curves and corrosion rate of sintered NdFeB in various solutions were tested.The surface morphology of sintered NdFeB corroded were investigated by means of SEM and AFM.The results indicate that corrosion of sintered NdFeB in hydrochloric acid and vitriol is most serious among all acid,and sintered NdFeB is passivated in phoshate and oxalic acid.The brim of sintered NdFeB is corroded rather seriously and the micro dimension was destroyed greatly in nitric acid.Every surface of magnet corroded by above acid becomes coarse.