During the determination of impurity elements in high purity molybdenum sample by inductively coupled plasma atomic emission spectrometry (ICP-AES), the matrix molybdenum had great interference with the determination of elements due to the abundant spectral lines of molybdenum. In order to eliminate the interference of matrix molybdenum with the determination of elements, the following pretreatment procedures were used: the sample was dissolved with hydrogen peroxide, then the matrix molybdenum was separated by precipitation with excessive nitric acid. The determination method of calcium, chromium, copper, cobalt, magnesium, nickel, zinc, cadmium and manganese in high purity molybdenum by matrix separation-inductively coupled plasma atomic emission spectrometry was established. The sample was dissolved with 4mL of hydrogen peroxide. The matrix molybdenum was precipitated with 10mL of nitric acid, and the precipitation efficiency was higher than 99%. After precipitation, the background equivalent concentrations of elements were all decreased. The recoveries were higher than 85% and the loss due to precipitation was low. The calibration curve was prepared using high purity molybdenum by the method of matrix separation. The linear correlation coefficients of calibration curves of all elements were higher than 0.9997. The limits of quantification were between 0.20μg/g and 2.03μg/g. The proposed method was applied for the determination of calcium, chromium, copper, cobalt, magnesium, nickel, zinc, cadmium and manganese in high purity molybdenum sample. The relative standard deviations (RSD, n=5) of the results were between 2.0% and 4.8%. The found results were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS).