In this study, aluminum dross, which is an industrial waste product from the aluminum casting industry, is used as an admixture in cement paste to observe its effects on the mechanical properties and the corrosion resistance in the reinforced steel bars. The mass ratios of cement and aluminum dross used to prepare the cement paste with the controlled water ratio of 48.5 wt.%are1.00:0.05, 1.00:0.1, and 1.00:0.2. The effect the mass ratios of cement and aluminum dross and the average particle sizes of the aluminum dross (<45, 60 and 90 μm in diameter) on porosity, bulk density, compressive strength, and corrosion on the reinforced steel bars have been centered around. The results show that as the quantity of the aluminum dross increases, the porosity of cement paste increases but the bulk density and compressive strength of the paste decrease. In addition, as the particle size of the aluminum dross increases, both pore's size and bulk density increase but the compressive strength decreases. Nevertheless, it found that the addition of aluminum dross to the cement paste causes more corrosion on reinforced steel bar and also more fractured on cement paste.