Anode slime is generated during copper elecrorefining process, and copper should be removed from anode slime to concentrate precious metals. Various oxidants such as ferric ion, nitric acid, hydrogen peroxide have been investigated to oxidize copper but there are some drawbacks such as NOx gas emission and unstable or complicated process. In the present study, new Cu leaching process was developed using sulfuric acid with cupric ion and oxygen. The Cu leaching behavior was investigated using four leaching sets; without aeration and cupric ion, with aeration but no cupric ion, with cupric ion but no aeration, with cupric ion and aeration. The leaching results showed the highest leaching efficiency by adding air and cupric ion. The Cu leaching efficiency increased to 98% in the 1 M sulfuric solution at 90 °C and 400 rpm with 1 % pulp density, 10000 ppm CuSO4, 300 cc/min air for 2 hours.