The　adsorption　of　O-2　on　the　perfect　and　low-coordinated　sites　of　MgO　(001)　surface　has　been　studied　with　the　finite　cluster　models　embedded　in　a　large　array　of　point　charges　by　density　functional　method.　The　point　charge　value　was　determined　by　self-consistence　technique.　Different　kinds　of　possible　models　Of　O-2　adsorbed　on　MgO　(001)　surface　were　calculated.　The　optimization　of　the　geometry,　calculation　of　the　adsorption　energy,　vibrational　frequency　and　analysis　of　the　Mulliken　population　to　those　adsorption　models　were　carried　out.　The　results　indicate　that　cationic　site　in　the　lowest　coordinated　corner　is　the　most　advantageous　position　for　O-2　adsorbed　on　MgO　(001)　surface.　The　O-O　bond　strength　is　considerably　weakened　when　O-2　lies　flatly　on　the　Mg　atom　at　the　corner(Mg-3c).　The　calculated　adsorption　energy　of　O-2　on　MgO(001)　perfect　surface　is　in　good　agreement　with　experimental　value.　For　O-2　adsorbed　on　the　perfect　surface　embedded　in　nominal　+/-　2.0　e　point　charges　and　on　perfect　surface　using　the　bare　cluster,　the　adsorption　energies　given　in　this　paper　show　that　they　have　a　large　deviation　from　the　experimental　value.　The　vibrational　frequency　of　adsorbed　O-2,　which　is　experimentally　difficult　to　measure　due　to　the　existence　of　isotope　exchange,　was　also　calculated.