Through thermally treating silicon nanoporous pillar array (Si-NPA) in a graphite crucible in a vacuum furnace at 1100 degrees C, a continuous thin film composed of cubic SiC nanoparticles was prepared and its room-temperature resistive sensing properties were measured. The sensor was found to be with high sensitivity and an upper limit concentration of 1200 ppm for H2S detection. Through carrying out the experiments of adsorption-desorption dynamic cycles and long-time air-ambient storage, the sensor was demonstrated to be with high repeatability and long-term stability. The response and recovery times were determined to be similar to 123 and similar to 114s, respectively. The sensing mechanism was put forward through analyzing the possible adsorption modes of H2S molecules on SiC/Si-NPA. The existence of the detecting limit concentration was attributed to the single-layer adsorption of H2S molecules, whose quantity was restricted by the effective adsorption sites formed on SiC/Si-NPA. Our results show that SiC/Si-NPA might be an ideal sensing material for fabricating low-concentration H2S gas sensors. (C) 2012 Elsevier B.V. All rights reserved.