This study tries to reveal the carbonation behavior when recycled coarse aggregates(RCAs) are used to mix new concrete.Six series of tests including 22 groups of recycled aggregate concrete(RAC) specimens were carried out,in which the effects of the water/binder(w/b) ratios,the binder content,the types of mineral admixture,the quality of RCAs,the RCAs replacement and the loading levels on the carbonation behavior of RAC were evaluated,respectively.The results showed that the carbonation behavior of RAC was not only influenced by the quality of new mortar but also by the properties of RCAs.The admixture of mineral admixture influenced the carbonation,and the loading stress level might have a significant impact on the evolution of the carbonation. This study tries to reveal the carbonation behavior when recycled coarse aggregates (RCAs) are used to mix new concrete. Mix series of tests include 22 groups of recycled aggregate concrete (RAC) specimens were carried out, in which the effects of the water / binder (w / b) ratios, the binder content, the types of mineral admixture, the quality of RCAs, the RCAs replacement and the loading levels on the carbonation behavior of RAC were evaluated, respectively. the results showed that the carbonation behavior of RAC was not only influenced by the quality of new mortar but also by the properties of RCAs. The admixture of mineral admixture influenced the carbonation, and the loading stress level might have a significant impact on the evolution of the carbonation.