The multilayer relaxation of Al(100),(110),(111) and (210),(211),(310),(311) and (331) surfaces is calculated using the modified embedded atom method. The results are in good agreement with the experimental data and first-principle calculations. Especially, the results for Al(100) and (111), which show “anomalous” behaviors in surface relaxation, that is both exhibit- expansions between the first two layers, are consistent with the experimental data. It is suggested- that these expansions are mainly due to the increase of electronic s state and the decrease of p state in the bonds between the first two layers.