Calcium silicate hydrates, CaO-SiO2-H2O (C-S-H), were studied as a chloride fixation material. C-S-H of two different Cao/SiO2 ratios were synthesized and burned with calcium chloride in a temperature range from 600degrees to 1000degreesC. Minerals with a chemical composition of (CaOSiO2CaCl2)-Si-.-Ca-. and 9CaO(.)6SiO(2)(.)CaCl(2) were identified by X-ray diffraction analysis. Comparing the diffraction intensity, it was found that the most efficient chloride fixation was attained when burned at 800degreesC. Changes in the morphology of silicate anion associated with burning and fixation of the chloride were studied in terms of chloride fixation capability using the trimethylsililation technique. It was confirmed that some silicate anions formed a glassy infinite chain where the chloride ions were fixed as a solid solution.