Abstract: A method for the determination of high-content of copper in copper materials by flame atomic absorption spectrophotometry using sub-sensitive spectral line at 249.20 nm is reported in this paper. The effects of sub-sensitive spectral line, acidity of testing solution，co-existent metallic elements on the determination of Co were studied. The precision test was implemented for standard solution with Cu concentration of 400 μg/mL with precision of better than 0.82%RSD (n=11). The method has been applied to the determination of copper in copper concentrate, copper sponge and copper sludge, in which the copper content is less than 75%. The results are in good agreement with those by other methods.