The interaction between precipitation and recrystallization and its effect on the properties of the re-aged Cu-Ni-Si alloy are discussed. The results indicate that the pre-aging process for Cu-Ni-Si alloy was responsible to the significant strengthening effect in re-aging process, and the re-aging strengthening effect with pre-aging at 450℃ for 8h was even more remarkable. Upon aging, a phenomenon of simultaneous in situ and discontinuous recrystallization was observed in the treatment of pre-aging and deformed Cu-Ni-Si alloy. On the formation and growth of recrystallization, the precipitated phases are coarsed or dissolved in the front of grain boundaries following a re-precipitation in the recrystallization area.