Treatment of waste by gasification emits lesser amount of pollutants, such as dioxin, NOx, SOx etc. compared to incineration process. Emission of air pollutants from such process can easily be controlled. The resulting gas from gasification consists of syngas which can be used as energy and slag can be recycled. Due to these advantages, interest for using gasification technology is increasing. In this study, we evaluated slag utilization produced from gasification of automobile shredder residue(ASR). Slag grain size varied according to the cooling system, basicity and plant process. X-ray diffraction analysis showed that the slag was present in amorphous form. The produced slag satisfied the standard for absorption, density for utilization of aggregate. Slag melted over 1450℃ as observed from differential scanning calorimeter(DSC) analysis. Slag meting temperature is considered possibly due to various recycling processes used.