It is well known that maximal utilization of the returns can be beneficial for cost reduction, preservation of natural resources and protection of the environment, by making them into recycled Al-Cu alloys. In this study,the influences of returns on the microstructure and mechanical properties of Al-Cu alloys have been investigated by means of optical microscopy and scanning electron microscopy. The results showed that the returns could be used to produce recycled Al-Cu alloys with fine and uniform microstructure and excellent mechanical properties,including ultimate tensile strength, yield strength and ductility. It was found that the maximum performance of the recycled Al-Cu alloy in their properties could be achievable when the returns content was 20wt.%, which gave 219 MPa, 87.16 MPa and 12.15% at as-cast state, and 525 MPa, 445.3 MPa and 14.14% after heat treated, in their tensile strengths, yield strengths and elongations, respectively. These values were much higher than those of primary alloy.