The method of manufacturing glass-ceramics using steel slag as a major raw material was described. Batch composition was studied based on phase diagram of CAS system and DTA curve. Crystallization phases were determined by using XRD and SEM. The results show that dominant crystalline phase is diopside. The shape of the diopside crystals is granule-like. The size of the crystals is about 1 μm. The method of manufacturing glass-ceramics with steel slag is a new and effective way for comprehensive utilization of steel slag. （From : No.1, 2006 Glass & Enamel）