The efficiency and mechanism in degradation of 2-methylisoborneol (MIB) as taste and odor compound in drinking water were studied under the condition where gamma-alumina catalyzed ozonation. As a result, gamma-alumina can behave distinct activity in enhancing the efficiency of ozonation MIB. Tert-butyl alcohol had a remarkable restrain effect on removal efficiency of catalytic ozonation MIB by gamma-alumina. The surface charge status and surface hydroxyl groups status of gamma-alumina and pH values of the solution can be linked together. When the pH value of solution was near the pH(zpc) of gamma-Al2O3, there was a most observable activity in catalyzed ozonation process. R(ct), which denoted the relative concentration of hydroxyl radical (*OH), was much higher in catalyzed ozonation process than in ozonation process. This result further illuminated that gamma-Al2O3 can promote ozone decomposition to produce *OH. Finally, it was investigated that the effect of r(P/I) on catalyzed ozone decomposition and ozone decomposition.