Carbonized recycled coarse aggregates（CRCAs） were obtained by recycled coarse aggregates（RCAs） modified under high concentration of CO2. The physical and mechanical properties of the natural coarse aggregate（NCA）， RCA and CRCA were experimentally investigated， and three types of concrete with different combinations of coarse aggregates， i.e.， NCA+RCA， NCA+CRCA， RCA+CRCA were designed and prepared， respectively. The results show that the apparent density， bulk density， water absorption and crushing index of CRCA are generally laid between those of RCA and NCA for the same coarse aggregate gradation. The concrete compressive strength increases with the increase of replacement of CRCA to RCA， whereas it decreases with the increase of replacement of CRCA to NCA. Also， the concrete compressive strength does not show obvious decrease when the replacement rate is smaller than 50%.