The effect of cold deformation and aging on the microstructure and properties of Cu-3Ti-2Mg alloy was investigated. The microstructure and phase constituents were characterized by optical microscope (OM), scanning electron microscope (SEM), X-ray diffractometer (XRD), transmission electron microscope (TEM) and electron backscattering diffraction (EBSD), and the hardness and electrical conductivity were measured as well. The results show that the microstructure of as-cast Cu-3Ti-2Mg alloy is consisted of Cu2Mg phase, plate-like Cu4Ti phase and Cu matrix. The microstructural characterizations revealed that the β′-Cu4Ti phase precipitate from the supersaturated Cu matrix during aging. However, excessive aging causes the phase transformation from metastable, coherent β"-Cu4Ti to equilibrium, incoherent Cu3Ti phases. In the range of experiments, the optimum process for Cu-3Ti-2Mg alloy is solutized at 700 °C for 4h, cold deformation of 60%, and aging at 450 °C for 2h. The electrical conductivity and hardness of Cu-3Ti-2Mg alloy are 16.7% IACS and 328 HV, respectively.