Abstract: A new method for the determination of phosphorus in casting aluminum alloy by ICP-AES was proposed in this paper. 0.500 0 g of the sample was dissolved completely with 12 mL of HNO3 (1+1)solution and 4 mL of HF. The spectral line of 213.618 nm was selected as analytical line for the determination. Linear relationship between values of emission intensity and mass concentration of phosphorus was kept in the range within 4.00 mg·L-1. Value of detection limit (3s/k) of the method found was 0.020 mg·L-1. The proposed method was used in the analysis of 5 standard materials of casting aluminum alloy, giving results in consistency with their certified values. Values of RSD′s (n=6) and recovery found were in the ranges of 0.43%-2.2% and 94.0%-109% respectively.