Granulite terrains exposed on the North China craton are the exhumed Precambrian lower crust, whereas the granulite-facies xenoliths entrained in volcanic rocks are representatives of the Phanerozoic lower crust. The comparative studies of granulite terrains and granulite xenoliths provide important constraints on the evolution of the lower crust beneath the North China Craton. Based on data available on the granulite terrains and granulite xenoliths, this paper discusses the modification of the lower crust beneath the North China Craton during the Phanerozoic mainly from the perspectives of zircon U-Pb ages and their Hf isotopic compositions. The lower crust was also significantly modified in company with the destruction of the mantle lithosphere since the Mesozoic, with the time and degree of modification varying from region to region. Magmatic underplating played the most important role in modifying the pre-existent ancient crust, while the remelting of the ancient crust was probably another way to modify the lower crust.