The　rod-like　tetragonal　alpha-MnO2,　flower-like　hexagonal　epsilon-MnO2,　and　dumbbell-like　tetragonal　beta-MnO2　were　prepared　using　the　hydrothermal　or　water-bathing　method　under　different　conditions.　It　is　shown　that　the　alpha-MnO2,　epsilon-MnO2,　and　beta-MnO2　catalysts　possessed　a　surface　area　of　ca.　53,　30,　and　114　m(2)/g,　respectively.　The　oxygen　adspecies　concentration　and　low-temperature　reducibility　decreased　in　the　order　of　alpha-MnO2　＞　epsilon-MnO2　＞　beta-MnO2,　coinciding　with　the　sequence　of　their　catalytic　activities　for　toluene　combustion.　The　well-defined　morphological　MnO2　catalysts　performed　much　better　than　the　bulk　counterpart.　At　a　space　velocity　of　20,000　mL/(g　h),　the　temperature　for　90%　toluene　conversion　was　238,　229,　and　241　degrees　C　over　alpha-MnO2,　epsilon-MnO2,　and　beta-MnO2,　respectively.　The　apparent　activation　energies　of　alpha-MnO2,　epsilon-MnO2,　and　beta-MnO2　were　in　the　range　of　20-26　kJ/mol.　It　is　concluded　that　higher　oxygen　adspecies　concentrations　and　better　low-temperature　reducibility　were　responsible　for　the　good　catalytic　performance　of　the　alpha-MnO2,　epsilon-MnO2,　and　beta-MnO2　materials.　(C)　2012　Elsevier　B.V.　All　rights　reserved.