MnOx supported on activated carbon (AC) with SiO2 encapsulated modification were prepared by impregnation method and employed for oxidizing gaseous benzene by catalytic ozonation. The encapsulation modification of SiO2 can prevent AC from oxidizing by O-3 and enhance the utilization of O-3. The MnOx/SiO2@AC catalyst with SiO2 encapsulation shows superior catalytic activity, the benzene removal efficiency and mineralization rate are 100% and 76.4%, respectively. The catalytic activity of benzene was also studied using MnSO4 and Mn(NO3)(2) as precursor solution. The optimal MnOx/SiO2@AC catalyst was characterized by XRD, XPS, SEM and TEM technologies. A possible catalytic ozonation mechanism of benzene over MnOx/SiO2@AC catalyst was proposed.