In　this　article,　kinetics　equation　of　the　metal　surface　oxidation　is　presented　using　the　perturbation　approach.　A　moving　boundary　is　converted　into　a　fixed　one　by　Landau　transformation.　The　perturbation　results　show　that　(1)　the　solution　of　the　zeroth-order　stands　for　the　quasi-steady　state　and　that　of　the　first-order　is　instantaneous　and　(2)　the　reaction　rate,　diffusion　coefficient,　and　the　thickness　of　the　initial　oxide　layer　have　important　effects　on　the　oxidation　kinetics.　If　the　chemical　reaction　is　supposed　to　be　instantaneous,　our　results　are　reduced　to　the　classical　parabolic　law,　no　matter　whether　there　exists　the　initial　oxide　layer　or　not.　Moreover,　the　kinetic　coefficient　of　the　parabolic　law　is　analytically　presented.　The　proposed　perturbation　scheme　can　be　easily　extended　to　the　higher　order,　and　the　higher　order　solution　will　provide　a　method　to　correct　the　error　offered　by　the　classical　model.　©　The　Author(s)　2017.