Partial oxidation of methane was carried out by ceria-promoted Ni-substituted hydrotalcite-derived catalysts ($Ce_xNi_3$-HTlc ; x=$0.3{sim}1.2$) in a fixed-bed reactor. The Ce/Ni ratio of 0.3/3 in the catalyst showed the best catalytic activity but the Ce/Ni ratio became higher above 0.3/3, the catalyst became less active in short-term tests. No ceria promoted catalyst was started to decrease $CH_4$ conversion after 20 h but the Ce/Ni ratio 0.3/3 catalyst was kept its stability in long-term tests.