H2S removal using Ca ion-exchanged coal char was studied in a fixed bed reactor at a temperature of 900 degrees C. Yallourn, an Australian brown coal was used for ion exchange. The CaO obtained from the pyrolysis of Ca ion-exchanged coal was finely dispersed in the char and much more reactive toward H2S than that from limestone. Ca ion-exchanged coal char showed high H2S capture and almost no emission of H2S was observed in the earlier reaction stage. At a reaction time of 100 min, the S/Ca atomic ratio in Ca ion-exchanged coal char increased to 1.2. This was due to H2S capture capacity of both the coal char itself and the CaO distributed in the char. The sorption capacity of char was determined as 1.5 mmol-H2S/g-char. The desulfurization characteristics of calcined limestone strongly depended on the particle size, whereas those of Ca ion-exchanged coal char was almost independent of the char particle size.