At Hot gas desulfurization, which is one of the unit process for Integrated coal Gasification Combined Cycle(IGCC) system, SO₂ was generated in the regeneration process of sorbents. SO₂ is a major atmospheric pollutant causing various ecological damages and health problems. Direct sulfur recovery process(DSRP) is the catalytic reduction of SO₂ to elemental sulfur by a reductant gas such as CO, H₂ or CH₄. In this work, the optimization of reaction condition such as the reaction temperature, space velocity and CO/SO₂ molar ratio in DSRP was performed. Sn-Zr compound was used as catalyst in DSRP. Especially, in this process, at low temperature of 598 K, elemental sulfur yield was very high. Generally, DSRP was performed at high temperature above 673 K. Therefore, this process has many advantage from the viewpoint of economy.