Transition metal oxide MnOx is widely used in catalytic decomposition of ozone because of its excellent activity and low price. In order to develop manganese-based oxide catalysts with stable catalysis capability in high humid condition for long time,the mechanism of ozone decomposition in humid air on manganese-based oxide catalysts was summarized, as well as the mechanism of deactivation of catalysts, the techniques to improve the water resistance of manganese-based oxide catalysts were concluded. In order to meet the future requirements of application, it was suggested to develop environmental-friendly manganese-based oxide catalysts for ozone decomposition with excellent water-resistance.