Abstract: ICP-AES was applied to the determination of total phosphorus in sewages after the sample was digested by microwave with a mixture of nitric acid, hydrochloric acid and hydrofluoric acid. The optimum experimental conditions were as follow:the RF power was 1 450 W, the observation height was 8 mm, the atomization gas flow rate was 0.85 L·min^-1, and the analytical line was P 213.617 nm. The linearity range of phosphorus was 0.10-50.0 mg·L^-1 with detection limit (3s) of 0.05 mg·L^-1. Recovery rates obtained by standard addition method were in the range of 92.7%-94.8% and RSDs (n=6) were in the range of 1.2%-2.6%.