The catalytic activity and durability of methane-steam reforming under a low H2O/CH4 molar ratio was studied on an Ni/Al2O3 catalyst prepared using water-in-oil (w/o) microemulsion. The initial activity of the prepared Ni/Al2O3 catalyst was higher than that of an impregnated one. The impregnated catalyst deactivated rapidly and lost its activity at a time-on-stream of 15 h due to severe coking (> 30 wt%-carbon after 20 h). In contrast, the catalyst prepared using w/o microemulsion sustained its activity for 40 h, and gave little coke (<0.3 wt%-carbon after 40 h) on the catalyst.