Many researchers investigated various concrete made with the cementitious materials, hence the effects of various admixture are well known. Most researches focused on an alternative cementitious material, tested concrete properties by varying the cement-replacement ratio. The optimum cement-replacement ratio may be different by each admixture. The present study examined the strength properties of concrete incorporating various admixtures. The cementitious materials tested in this study were fly-ash, blast furnace slag powder, silica-fume, limestone powder, and an artificial admixture which has high resistance to chloride attack. First, fundamental properties of the concrete incorporating the admixture were summarized referring to previous durability tests. Second, the strength properties of concrete made with some cement-replacement ratios by the cementitious materials were examined. In addition, alternative cement efficiency factors (k) of each cementitious material were estimated.