A method for determination of Chromium(VI) by reversed flow injection spectrophotometry based on the catalytic effects of chromium on the oxidation reaction of methylene blue by sodium periodate in sulfuric acid medium is established. Effects of concentration of reagents and other conditions have been optimized. Calibration graphs are linear for ranges of 0 to 1.0mgl−1. A detection limit of 0.007mgl−1 chromium is achieved. The proposed method is successfully applied to the analyses of industrial waste water and electroplating waste liquor, with relative standard deviation of less than 1.5% and the recoveries are 92.9％ to 97.5％for the determination of chromium.