Abstract: The effects of illumination manners on the photocatalytic degradation of organic contaminantswere studied with the TiO2 /ITO photoanode. The degradation process and the hole scavenging abilitywere analyzed by light intensity test. The results showed that the photocatalytic degradation rates of phe-nol,humic acid and acid orange under backside illumination increased by 16.19%,26.09% and38.87%,respectively,compared with those under positive illumination. That was because theillumination intensity of positive illumination lost when the light passing through the solution,thus theillumination intensity on the surface of the photoanode reduced. The increased degradation rate of or-ganic pollutants under backside illumination was positively correlated with the light adsorption ability oforganic pollutants. The backside illumination improved the hole trapping ability by avoiding the illumi-nation loss,resulting in a larger photocurrent compared with the condition without contaminants. Close-