To abate NO in exhaust, a series of copper-aluminate catalysts were prepared by calcination at high temperature with high surface area support. Variables were Cu loadings and calcination temperatures. Characterization results show that a copper aluminate phase is formed with spinel type structure through high calcination temperature and copper lending. The activity and stability for NO reduction were studied in a lab. scale reactor in the presence of excess oxygen. The reducing agent was C3H6 or NH3. The catalyst, calcined at high temperature showed enhanced activity in the presence of C3H6, but copper aluminate species, formed hy calcination at high temperature, have no effect on NO conversion when NH3 is used as the reducing agent. Engine dynamometer test showed that C3H6 is more effective than C2H5OH to abate nitric oxide with 10 wt.% copper loaded aluminate catalysts.