In order to improve the in situ oxidation kinetic condition of Al in Cu matrix, Cr, instead of Al was in situ oxidized to form Cu/Cr 2 O 3 composites in the present investigation, CuCr powders with different solubilities after mechanical activation were utilized to synthesize Cu/Cr 2 O 3 composites, and their microstructure and stability were analyzed. The results show that although the CuCr powders suffer from the same mechanical activation; Cr 2 O 3 particles formed by the powders with different solubilities have great differences in size, amount, and distribution. In the range of experiments, the Cu/Cr 2 O 3 composite formed by CuCr powders with 67% solution has large amounts of finer Cr 2 O 3 particles uniformly distributed in Cu matrix and the best stability at elevated temperatures.