The purpose of this study is to provide wasted concrete which could be help for the recycling of the waste concrete and the reduction of carbon dioxide, those are an issue that gives rise to enormous controversy. The way of the experiment in chemistry is to inject carbon dioxide into aqueous solution made by calcium hydroxide using the Pressure Reactor. Before conducting the experiment, the existing studies based on the material, the mechanism of hydroxylation, carbonation and the solidification were considered. As a result, it was measured how much carbon dioxide is absorbed by the aqueous solution and it was confirmed how much calcium carbonate is producted. Therefore, the amount of carbon dioxide absorbtion in the 1m3 waste concrete was quantitatively predicted. In addition, the crystal structure and the degree of purity of calcium carbonate was analysed by FE-SEM. It could be an fundamental data to decrease both carbon dioxide and waste concrete, especially waste cement mortar powder. It also would a higher value-added business because of the product, calcium carbonate.