A porous SiO2-doped TiO2 photocatalyst was prepared through co-sol-gel method used for photocatalytic degradation of methyl orange. PEG1000 was used as a template. Photocatalytic degradation was conducted after adsorption equilibrium to identify the contribution of both adsorption and photocatalytic degradation. While PEG addition ranged from 0.25 g to 1.0 g, the optimum addition amount was at 0.5 g. The degradation rate increased with increasing calcination temperature in the range from 400 to 500 oC, and then it decreased with still increasing temperature. The photocatalyst calcinated at 500 oC for 4 h could degrade 29.2% of the initial methyl orange in 30 min. Nearly 96.5% of decoloration of the initial methyl orange was removed in 100 min under UV light irradiation with the existence of the porous SiO2-doped TiO2.