The hardness measurement,optical microscopy (OM),and transmission electron microscopy (TEM) microstruc-ture observation on the annealing behaviors of Cu-Al2O3 (2.25 vol.% and 0.54 vol.% Al2O3) and Cu-0.52vol.%Nb alloys were carried out. The results show that with the increase of annealing temperature,the hardness of Cu-Al2O3 alloys de-creases slowly. No change of the fiber structure formed by cold rolling in the Cu-2.25vol.%Al2O3 alloy is observed even af-ter annealing at 900°C,and the higher dislocation density can still be observed by TEM. Less combination of fiber formed by cold rolling and subgrains are observed in the Cu-0.54vol.%Al2O3 alloy annealed at 900°C. With the increase of anneal-ing temperature,the hardness of the Cu-0.52vol.%Nb alloy exhibits a general decreasing trend,and its falling rate is higher than that of the Cu-Al2O3 alloys,indicating that its ability of resistance to softening at elevated temperature is weaker than that of the Cu-Al2O3 alloys. However,when annealed at a temperature of 300-400°C,probably owing to the precipitation strengthening of niobium,the hardness of the Cu-0.52vol.%Nb alloy arises slightly. The fibers formed by cold rolling be-come un-clear and un-straight and have less combination,and considerably more subgrains are observed by TEM. The hardness measurement, optical microscopy (OM), and transmission electron microscopy (TEM) microstruc-ture observation on the annealing behaviors of Cu-Al2O3 (2.25 vol.% And 0.54 vol.% Al2O3) and Cu-0.52 vol.% Nb alloys The results show that with the increase of annealing temperature, the hardness of Cu-Al2O3 alloys de-creases slowly. No change of the fiber structure formed by cold rolling in the Cu-2.25 vol.% Al2O3 alloy is observed even Less combination of fiber formed by cold rolling and subgrains are observed in the Cu-0.54 vol.% Al2O3 alloy annealed at 900 ° C. With the increase of anneal-ing temperature, the hardness of the Cu-0.52 vol.% Nb alloy exhibits a general decline trend, and its falling rate is higher than that of the Cu-Al2O3 alloys, indicating that its ability of resistance to softening at elevated temperature is weaker than that of the Cu-Al2O3 alloys. However, when ann The fibers formed by cold rolling be-come un-clear and un- straight and have less combination, and considerably more subgrains are observed by TEM.