Abstract: The physical index of recycled coarse aggregate is far lower than that of natural coarse aggregate due to the existence of residual mortar, which leads to the poor mechanical properties and durability of recycled aggregate concrete (RAC). Furthermore, the ingress of water and aggressive ion is the main cause of the degradation of concrete properties. The durabilities of concrete with various replacement ratios by mass of recycled concrete aggregate(0%, 30%, 50%), which has been impregnated by 8wt% silane, were studied through a series of tests, including the compressive strength, capillary water absorption and chloride penetration depth. Finally, the microstructure of the recycled concrete was analyzed by SEM. The experimental results show that the water absorption rate of the recycled coarse aggregate treated by silane impregnationis decreases significantly, and the compressive strength of the recycled concrete prepared by silane decreases slightly. Moreover, the capillary water absorption of the modified recycled concrete is obviously reduced while the chloride penetration resistance is significantly increased. The chloride diffusion coefficient of the treated recycled concrete with the aggregate replacement ratio by mass of 50% is reduced by 37.5%. This research indicates that the recycled coarse aggregate impregnated by silane is an effective way to improve the durability of the recycled aggregate concrete.