Steam gasification of three different coal chars and activated carbon has been carried out in a fixed-bed reactor under the conditions of 650-1000℃ and 0.1-0.7atm of steam. Three sample coale are Korean Jangsung anthracite, Chinese Tatong bituminous and Indonesian lignite. The gasification rate, estima-ted from G.C. analysis of the product gases, increases initially in parallel with the surface area of the reacting char, reaching the maximum when the carbon conversion is about 5-15%. Mechanism of the char gasification is well represented by the unreacted shrinking-core model. Chars of the lower-rank coals exhibit relatively fast gasification rates at low temperatures, but the bituminous coal char shows a significant increase in the gasification rate at higher temperatures. The CO₂/CO and H₂/CO molar ratios among the products and the activation energy of CO formation decrease with increasing rank of the sample coals.