Abstract: The influences of coarse aggregate replacement rate，coarse aggregate strengthening treatment with improved mixing， fly ash, silica fume on the resistance to the chloride ion permeability into the recycled coarse aggregate concrete are studied in this paper. The experiment results indicate that the resistance to the chloride ions permeability must decrease with the increase of a recycled aggregate replacement rate. When there are the replacement rates of 0，30%, 50%, 70% and 100%, 6 h electric charges are respectively 2 090, 2 596, 3 207, 3 989 and 5 182 C, with the chloride ion permeability level moving from the moderate to the high. Reinforcing the process of the concrete aggregate and improving the mixing process can improve the resistance to chloride ion permeability of the recycled concrete. As the recycled aggregate replacement rate is below 50%，the resistance to chloride ion permeability of the recycled concrete is close to that of the ordinary concrete after strengthening with twice packages or by improved stirring process. Mixing fly ash or silica fume alone or mixing both at the same time can significantly improve permeability resistance to the chloride ion into the recycled concrete， and the silica fume is better than fly ash in this respect. 20% fly ash admixed with 10% silica fume can be regarded as the best dosage, 6 h electric charge is 171 C, and the high-performance recycled concrete having higher permeability resistance to the chloride ion can be made up by this way. The experiment results would provide a strong basis for popularization and application of the recycled concrete in civil engineering.