Rhodium is widely used in automotive catalysts, gas sensors, biomedical, chemical industry and etc. While its purity will directly affect the performance of the product, therefore , the accurate determination of the content of impurities in rhodium is of great importance. At present, the commonly used detection methods are inductively coupled plasma emission spectrometry (ICP-AES) and glow discharge mass spectrometry (GDMS). The data obtained by the two detection methods are compared with the Six Sigma statistical method, and the cause analysis and improvement of the significant different results are carried out.