Abstract: DC arc atomic emission spectrometry was adopted to determine cadmium content in niobium and niobium alloy with pure cadmium oxide as the spot, cadmium 226.502 nm the analysis line and the ration of sample to buffer 2 to 1.Results showed that by this method, the dection limit was 0.84 μg/g, the recovery rate was between 94.7%~108.7%, and the relative standard deviation (n=11) was lower than 10%, presenting high accuracy and precision.