Abstract: It was reported in this paper that in the AES analysis of aluminum alloy ingots by the photoelectric direct reading spectrometer,segregation of alloying elements,especially silicon in the alloy was observed,leading to deviation of analytical results obtained from different site of excitation.By improving the method of sampling of taking the sample cubes in the vertical section instead of from both end and middle of the alloy ingot,the analytical results obtained were in consistency,and the deviations found were quite small values and reasonable.