Existing concrete radiation shielding has been studied for many. However, research in progress using steel slag aggregate was not. Recently, worldwide propose to preserve the global environment and energy, the waste of human resources improvement, and resources to build a recycling-oriented society. The steel slag, a by-product which is produced during the manufacture of steel by refining pig iron, has generated about 20 million tons yearly. However, it is difficult to recycle steel slag as aggregate for concrete because the reaction with water and steel slag could make the expansion of volume. Recently, many studies throughout the steel slag can be recycled. In this study, using high specific gravity of steel slag coarse aggregate and fine aggregate were developed for radiation shielding concrete.