Abstract: The Al content in CO combustion promoter is high, which has a significant influence on the determination of Pt content. The effect of matrix matching method and internal standard method on eliminating matrix interference in the sample was investigated with actual samples. A method to eliminate the matrix interference of Al by using these two methods was established. By comparing several sample treatment techniques, then the high temperature melting technology was determined to be used to prepare CO combustion promoter and the inductively coupled plasma emission spectrometry (ICP-AES) was used to determine Pt content in CO combustion promoter. The correlation coefficient of Pt calibration curve is 0.999 93. The precision and accuracy of the samples were also investigated. The relative standard deviation of the results was less than 2%, and the recovery rate was 98%-102%.