The aerogels of nickel-alumina system have been synthesized from aluminum triisoprppoxide and nickel glycoxide by sol-gel and subsequent supercritical drying, and the catalysis of NiO-Al2O3 aerogels for the methane reforming by carbon dioxide have been examined. The aerogel catalysts showed higher activity for the reforming than the impregnation catalysts prepared by a conventional impregnation method, on the other hand, the carbon deposition was much less significant on the aerogel catalysts than on the impregnation catalysts. By TEM and XRD observations, it was found for aerogel catalysts that fine nickel particles were formed throughout the alumina aerogel support with high dispersion. This resulted in not only higher catalytic reforming activity but also much less coking activity. The suppression of catalyst deactivation during the reforming was ascribed to the retardation of both carbon deposition and sintering of nickel particles on alumina aerogel support.