This paper generalized the structure characteristics of three different configuration photoreactors: annular-type irradiated by lamp, solar shallow-pond and solar flat-plate and compared their performance efficiency at the same reaction condition level which was determined by the first order rate constant in photocatalytic decolorization of methyl orange in TiO2 suspension. It was demonstrated that solar could be considered as an altative light source in photoreactors not only for low running and construction cost but also for their successful performance. The evidence has proved the feasibility of solar photocatalytic oxidation as an additional or altative advantage stage of wastewater treatment process.