CO2 reforming of methane into syngas over Sm2O3-La2O3 (SL)-supported Ni catalyst was investigated in a fixed-bed quartz reactor and the best catalytic activity was observed over Ni/SL (sol-gel) due to the reduction of the perovskite LaNiO3 and spinel La2NiO4 to form small nickel particles. The conversion of CH4 and CO2 over Ni/SL(sol-gel) were 55% and 57%, respectively, the selectivity of H-2 and CO were 96% and 98%, significantly higher than those over Ni/SL (imp) catalyst at 700 degrees C and a GHSV of 4.8 x 10(4) mL.h(-1).g(cat)(-1). In the meantime, the Sm2O3-La2O3-supported Ni catalysts were characterized by means of techniques, such as BET, XRD, H-2-TPR, TG/DTA, HRTEM, XPS, and XAES.