Al/Al 2 O 3 multilayers were deposited on sintered NdFeB magnets to improve the corrosion resistance. The amorphous Al 2 O 3 films were used to periodically interrupt the columnar growth of the Al layers. The structure of the multilayers was investigated by Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). It was found that the columnar structure was effectively inhibited in the multilayers. Subsequent corrosion testing by potentiodynamic polarization in 3.5wt.% NaCl and neutral salt spray test (NSS) revealed that the Al/Al 2 O 3 multilayers had much better corrosion resistance than the Al single layer. Furthermore, for multilayers with similar thickness, the corrosion resistance was improved as the period decreased.