Abstract: The determination method of impurity metal elements in the neptunium dioxide powder was built by ICP-AES, which could detect twelve impurity metal elements such as calcium, beryllium, cadmium, etc. In this work, a HNO₃-HF acid system was used to dissolve the neptunium dioxide powder in polytetrafluoroethylene crucible, then the solution was dealt with TEVA resin column after valence adjustment, and the sample test solution was detected by ICP-AES. The results show that the optimum analytical conditions are as follows: Sample dissolution adjusted with hydrogen peroxide about 5 min, sample amount of 30 mg, and 5 mol/L nitric acid as eluent. Under these conditions the recoveries of most elements are more than 95%, the relative standard deviations (n=6) are between 0.6% and 4.8% with 93%-108% recoveries, and the detection limits of this method are 0.07-8 μg/g.