The concrete materials are used as the partition wall of the tritium handling facilities. It is important to grasp the tritium behavior in the concrete wall for radiation safety. It is considered in this study that the surface water on the concrete materials consists of physically adsorbed water, chemically adsorbed water and structural water as in the case of porous adsorption materials. The adsorption capacity due to physically and chemically adsorption isotherms observed in this study shows that the amount of water adsorption on the cement paste is a quarter of the amount adsorbed onto the surface of activated alumina or molecular sieves 5A (MS-5A). It shows that concrete is easily contaminated with tritiated water.