H2S poisoning is an important issue for solid oxide fuel cells (SOFCs) operated with syngas. The effect of simulated coal-derived gas composition on H2S poisoning behavior was evaluated using a disaggregation scheme where the influence of H-2 content was determined separately using a typical anode-supported SOFC operated with a N-2/H-2 mixture gas, while the effect of other compositions (CO, CO2, and H2O) was investigated with simulated coal-derived gas having constant H-2 and CO flow rates balanced by a H-2/N-2 mixture gas (83% H-2 and 17% N-2). The results indicated that the extent of H2S poisoning was not pertinent to H-2 content when the cell was tested galvanostatically with a current density of 0.3 A/cm(2) at 800 degrees C using a N-2/H-2 mixture gas containing 10 ppm H2S, and the H2S poisoning impact can be completely removed by switching to sulfur-free gas. The CO, CO2, and high water vapor content aggravated the H2S poisoning effect, and the performance was almost irrecoverable when the cell was tested with a 35% H-2-46% CO-16% N-2-3% H2O mixture gas containing 12.5 ppm H2S. However, the introduction of 10% CO2 and an increase in H2O content from 3 to 10% in the mixture gas can promote the performance recoverability to a larger extent. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3232006] All rights reserved.