The properties of the carbonated brick made of steel slag-slaked lime mixture such as strength, drying shrinkage, water absorption and soundness were mainly investigated. The experimental results indicate that, after carbonation, the strength of the brick increases, its drying shrinkage reduces, and its soundness becomes eligible. The optimal slaked lime/steel slag(SL/SS) ratio for the carbonated brick is 0.2 and the asprepared brick meets the requirements of the Chinese standard for MU20-grade building bricks, additionally, it also demonstrates prominent environmental benefits. The XRD and pore structure analyses indicate that the excellent properties of this carbonated brick are attributed to the formation of carbonate crystals and the dense structure due to the carbonation. The properties of the carbonated brick made of steel slag-slaked lime mixture such as strength, drying shrinkage, water absorption and soundness were mainly investigated. The experimental results that that after carbonation, the strength of the brick increases, its drying shrinkage reduces, and its soundness becomes eligible. The optimal slaked lime / steel slag (SL / SS) ratio for the carbonated brick is 0.2 and the asprepared brick meets the requirements of the Chinese standard for MU20-grade building bricks, additionally, it also illustrative prominent environmental benefits. The XRD and pore structure analyzes indicate that the excellent properties of this carbonated brick are attributed to the formation of carbonate crystals and the dense structure due to the carbonation.