Abstract: In view of cement calciner technology, the sulfur-fixation properties of cement raw material during its combustion were evaluated by SC-132 sulfur analyzer. The mineral composition and microstructure of calcined sample were analyzed by XRD and SEM. The micro-mechanism of sulfur-fixation reaction at high temperature was discussed. The results show that thermal stability of sulfur retention mineral is a crucial factor in affecting the sulfur-fixation efficiency at high temperature. Cement raw materials have good sulfur-fixation ability within the temperature range tested. The sulfur-fixation efficiency is above 85% at 850 ℃～1 300 ℃. CaSO4 is formed at 850 ℃ and begins to decompose at 1 050 ℃. The thermal-proof complexes of 3CaO·3Al2O3·CaSO4 and Ca5(SiO4)2SO4 are formed at 1 050 ℃～1 250 ℃. The eutectic phase of ferroaluminate and silicate formed at 1 300 ℃ envelop the surface of CaSO4 and suppress its further decomposition, which results in the high efficiency for sulfur-fixation of cement raw materials at 1 300 ℃.