This　article　considers　the　dynamic　equation　of　a　reduced　model　for　thin-film　micromagnetics　deduced　by　A.　DeSimone,　R.　V.　Kohn　and　F.　Otto　in　[　A.　DeSimone,　R.　V.　Kohn,　F.　Otto,　A　reduced　theory　for　thin-film　micromagnetics,　Comm.　Pure　Appl.　Math.　55　(　2002)　1-53].　To　derive　the　existence　of　weak　solutions　under　periodical　boundary　condition,　the　authors　first　prove　the　existence　of　smooth　solutions　for　the　approximating　equation,　then　prove　the　convergence　of　the　viscosity　solution　when　the　viscosity　term　vanishes,　which　implies　the　existence　of　solutions　for　the　original　equation.　(C)　2009　Elsevier　Inc.　All　rights　reserved.