Abstract: Cerium is a critical rare earth element for improving the comprehensive properties of high thermal conductivity and high strength magnesium alloy applied in lightweight automotive radiators.However,due to the large size and irregular shape of such structural components,the conventional analytical methods are difficult to realize the rapid and accurate determination of low content cerium.In this study,an analytical method based on inductively coupled plasma atomic emission spectrometry(ICP-AES) was established.The homogeneity of samples was verified by F-test.The sample was dissolved with 25 mL of hydrochloric acid(1+1),and the matrix matching method was adopted to eliminate the influence of matrix effect.Under the analytical spectral line of Ce 404.076 nm,cerium showed a good linear relationship in the range of 1.00-12.00 μg/mL,with a linear correlation coefficient(r) of 0.999 9.The limit of detection was 0.000 34%.The proposed method was applied for the determination of cerium in certified reference materials magnesium alloy,and the relative errors(RE) ranged from -0.89% to 3.16%.The content of cerium in high thermal conductivity and high strength magnesium alloy profile sample for lightweight automotive radiator was determined according to the experimental method.The relative standard deviations(RSD,n=6) were between 0.44% and 1.7%,and the recoveries were between 92.5% and 102.3%.This method was suitable for the accurate determination of low content cerium in magnesium alloy profile for radiators,and it provided a reliable analytical technique for material performance evaluation.