Multiwalled carbon nanotube (MWCNT)-doped Al2O3 (MWCNT-Al2O3) was prepared by sol-gel method. MWCNT-Al2O3 was then used to prepare TiO2/MWCNT-Al2O3 for the photocatalytic degradation of methyl orange and was found to have degradation rate of 99.4 % in 1 h, which is much higher than that of P25 and TiO2/Al2O3. The physicochemical properties of TiO2/MWCNT-Al2O3 were characterized by XRD, BET, HRTEM, UV-Vis, and PL. TiO2 was found to be highly dispersed on MWCNT-Al2O3 and to have specific surface area of 309.75 m(2)/g after MWCNTs were introduced. The increased degradation efficiency was attributed to the synergistic effect between MWCNTs and Al2O3. The combination of MWCNTs and Al2O3 led to increased specific surface area, mesoporosity, and stability, as well as more extensive electron-hole pair generation, transfer, and separation.