The catalytic performance during combined steam and carbon dioxide reforming of methane (SCR) was investigated on Ni/MgAl2O4 catalyst promoted with CeO2. The SCR catalyst was prepared by co-impregnation method using nickel and cerium metal precursors on hydrotalcitelike MgAl2O4 support. In terms of catalytic activity and stability, CeO2-promoted Ni/MgAl2O4 catalyst is superior to Ni-CeO2/Al2O3 or Ni/MgAl2O4 catalysts because of high resistance to coke formation and suppressed aggregation of nickel particles. The role of CeO2 on Ni/MgAl2O4 catalyst was elucidated by carrying out the various characterization methods in the viewpoint of the aggregation of nickel particles and metal-support interactions. The observed superior catalytic performance on CeO2-promoted Ni/MgAl2O4 catalyst at the weight ratio of MgO/Al2O3 of 3/7 seems to be closely related to high dispersion and low aggregation of active metals due to their strong interaction with the MgAl2O4 support and the adjacent contact of Ni and CeO2 species. The CeO2 promoter also plays an important role to suppress particle aggregation by forming an appropriate interaction of NiO-CeO2 as well as Ni-MgAl2O4 with the concomitant enhancement of mobile oxygen content.