Cu/carbon nano-particle hybrids were fabricated through the cathodic electrophoretic deposition (EPD) process. CNT and CNF nano-particles were modified to give positive charges by polyethyleneimine (PEI) treatment before depositing them on the substrate. Since a Cu plate was used as an anode in the EPD process, Cu particles were also deposited along with the carbon nano-particles. Experimental observation showed the nano-hybrids constructed a novel formicary-like nano-structure which is strong and highly conductive. Utilizing the hybrids, carbon fiber composites were manufactured, and their electrical conductivity and interlaminar shear strength were measured. In addition, the deposition morphology and failure surface were examined by SEM observations. Results demonstrated that the electrical conductivities in the through-the-thickness direction and the interlaminar shear strength significantly increased by 350~2100% and 14%, respectively.