Different　crystallographic　structures　of　Mn　oxides　usually　lead　to　diverse　coordination　geometries　and　oxidation　states　of　MnO6,　which　in　turn　show　strikingly　different　catalytic　activities.　In　this　study,　methane　oxidation　performances　over　Mn　oxides　with　various　crystalline　structures　were　investigated,　including　alpha-MnO2　(double　chains　of　Mn4+O6　octahedra),　alpha-Mn2O3　(symmetry-inequivalent　Mn3+O6),　two-dimensional　mesoporous　beta-MnO2　(labels　as　Meso-MnO2,　single　chains　of　Mn4+O6　octahedra)　and　one-dimensional　beta-MnO2　(single　chains　of　Mn3+/4+O6　octahedra).　The　results　demonstrate　that　the　methane　oxidation　activities　are　dependent　on　their　crystallographic　structures,　and　follow　an　order　of　alpha-MnO2　＞　beta-MnO2　＞　alpha-Mn2O3　＞　Meso-MnO2.　Meanwhile,　alpha-MnO2　exhibits　good　durability　and　excellent　9.5vol%H2O/10vol%CO2　resistance　ability.　EXAFS,　Raman,　XPS,　O-2-TPD-MS　and　CH4-TPR-MS　studies　indicate　that　the　outstanding　catalytic　activity　over　alpha-MnO2　is　due　to　higher　surface　Mn　concentration,　more　active　oxygen　species　and　monoli-mu-oxo　bridged　corner-shared　[MnO6]　sites,　and　excellent　reducibility.　More　importantly,　a　new　insight　into　reaction　mechanism　of　methane　oxidation　over　Mn　oxides　was　proposed　at　the　molecular　level.