Abstract: The sulfur-fixing tests show that the sample D₉ from the profile of Dayu river possesses highest sulfur-fixing rate among three sections of the Ordovician limestone in Chenghe mining area.The sulfur-fixing rate is 60.08% under 1000℃ when the sample is calcined under 800℃ for 2 h and broken into powder in size of 0.12~0.15 mm,then mixed with coal powder in mole proportionality of Ca/S equaling to 2.3.