NiaCe/SiO2 catalysts were prepared by calcination under Ar, CO2, O2 and H2 ambience, and applied in CO2 reforming of methane for synthesis gas production. BET, XRD, XPS, TPR, SEM, TEM and TPH techniques were employed to characterize the fresh and used catalysts. Highly dispersed nickel oxides bearing stronger interaction with SiO2 prevented the metal sintering. The formation of reactive carbon species on NiaCe/SiO2 catalyst calcined under Ar ambience effectively promoted the carbon elimination and kept the catalyst more stable. Nevertheless, the oxygen storage capacity of CeO2 might partly lose on NiaCe/SiO2 calcined under H2 ambience. As a result, the inhibition of carbon elimination and the deposition of inert carbon were responsible for its partial deactivation.