The dry reforming of methane (DRM) was performed on the Al-promoted CoAl(x)/ZrO2 catalysts (x = 0 - 2 wt. %). The addition of a small amount of Al led to an apparent promotional effect on the catalytic activity and stability of the Co-based catalyst. The largest promotional effect was observed for the Co/ZrO2 catalyst with 1 wt. % of Al loading. Although the Co/ZrO2 catalyst exhibited considerable catalytic activity, it was rapidly deactivated during the DRM, while the Al -promoted catalysts exhibited a stable catalytic activity. The addition of appropriate amount of Al species might be caused the strong interaction with the cobalt species at either the ZrO2 surface or near the interfacial region. Thus, the Al promoter led to the enhancement of the catalytic performance of Co/ZrO2 catalyst system by acting as a structural stabilizer.