Graphene reinforced copper matrix composites have wide application prospects due to its good elec. and thermal conductivity, mech. properties and self-lubrication. However, weak interfacial bonding caused by the large difference in thermal expansion coefficient between Cu and GNPs is the main reason for the poor comprehensive performance of GNPs/Cu composites. In this study, (TiCp +GNPs)/Cu composites were successfully prepared by powder metallurgy and in-situ synthesis. The interfacial bonding was improved by in-situ reactions between titanium (Ti) and GNPs, which enhanced the comprehensive performance of GNPs/Cu composites obviously. Results show that TiCp was formed at the interface, accompanied Cu-Ti metallic compound in the matrix. The parallel orientation relationship ((011)CuTi// (011)TiC// (200)CuTi2) of the TiCp to the Cu-Ti metallic compound was observed, which revealed the formation mechanism of TiCp. Furthermore, good interfacial bonding was realized and strengthening efficiency of GNPs was greatly improved by regulating sintering parameters. An optimal balance between ultimate tensile strength and impressively lager plastic deformation was achieved at 900 °C x 2 h. Simultaneously, the in-situ synthesized TiCp played rivet roles in strengthening GNPs/Cu interfacial bonding and preventing crack propagation, which was beneficial to improving mech. properties of Cu matrix composites.