Carbonation of concrete causes reduction of pH and subsequently causes steel corrosion for reinforced concrete structure. However, for plain concrete structure or PC product, it can lead to a decrease in porosity, high density, improvement of concrete, shrinkage-compensation. Recently, based on this theory, research of CO2 curing effect has been performed, but it was mainly focused on its effects on compressive strength using only ordinary portland cement. Researches on CO 2 curing effect for concrete containing CO 2 reactive materials such as γ-C 2 S, MgO haven't been investigated. Therefore, this study has performed experiments under water-binder ratio 40%, and the replacement ratios of γ -C2S and MgO were 90%. Micro-chemical analysis, measurement of compressive strength according to admixtures and CO 2 curing were investigated. Results from this study revealed that higher strength was measured in case of CO2 curing compared with none CO2 curing for plain specimen indicating difference between 1.08 and 1.26 times, in case of γ -C2S 90, MgO 90 specimen, incorporating high volume replaced as much as 90%, it was proven that when applying CO 2 curing, higher strength which has difference between 14.56 and 45.7 times, and between 6.5 and 10.37 times was measured for each specimen compared to none CO2 curing. Through micro-chemical analysis, massive amount of CaCO3, MgCO3 and decrease of porosity were appeared.