Concrete truly is a building material. It can be used in many fields as building structures, shielding materials as concrete biological shield surrounding the reactor pressure vessel, radioactive waste cementation and even decorative objects. As a result, it is important to inspect some parameters of concrete structures. For achieving this aim, an industrial computed tomography (CT) system was designed and developed on the base of the first generation CT system. The CT scanner consists of a 50.8mm NaI(Tl) detector in diameter and a 137Cs (30 mCi) radioactive source. The position of phantom was defined by three motors. The CT scans were taken out in one dimension and total count for each gammametry of concrete was 15 minutes. In this study, several concrete cylindrical specimens of various components were prepared. Internal structures of the specimens were considered using industrial gamma CT apparatus to compare homogeneous and linear attenuation coefficient (that has direct relation with total density and atomic number, etc). After that, the special software was prepared for determination of homogeneity and attenuation coefficient. Consequently, the greater homogeneity and density give the higher quality and durability especially for using in concrete shield surrounding the reactor pressure vessel.