Abstract: Experiments were performed to evaluate the efficiency of benzene decomposition by using packed-bed coaxial cylindrical dielectric barrier discharge reactor. The packed beds were filled with glass beads with a diameter of 3 mm. The catalysts prepared were 8% Mn/γ-Al2O3, 8% Fe/γ-Al2O3 and 8% Co/γ-Al2O3. The benzene was allowed to have access into the air inlet of the reactor before being introduced into the discharge regions in quartz glass tubes. Then it passed by discharge regions of the packed-beds, and finally flew out. The experiments were conducted to investigate the packed beds with or without glass beads, the initial concentration of benzene and the catalysts' effect on the degradation of benzene respectively. The results indicate that higher efficiency is achieves with the packed beds filled with glass beads; with the increasing of initial concentration of benzene, degradation efficiency of benzene decreases; the order of the degradation efficiency of the catalysts is Mn>Co>Fe.