Mechanical properties of PVC[poly(vinylchloride)] composites containing the dust from blast and converter (Kwangyang Iron Co.) were investigated as a function of dust content. Tensile strength is increased, when the blast dust is mixed with PVC to the extent of 8.83wt% and impact strength is not significantly changed. From these results, it is suggested that blast dust containing CaO, SiO, MgO, Al₂O₃ and metallugical particle is compatible with PVC. Thermogravimetric analysis(TGA) showed that residual weight(%) at temperature 600℃ increased with the amount of blast dust and differential scanning calorimetry(DCS) showed that the thermal stability of PVC composite was increased when the weight ratio of blast dust was 8.83wt%. X-ray diffractometry measurement also showed their blends and structures.