By performing X-ray diffraction (XRD), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), and ammonia temperature programmed desorption (NH3-TPD) analyses, this study investigates the promoting effect of molybdenum on CuO/gamma-Al2O3 catalyst for the oxidative decomposition of (CH3)(2)S-2. Experimental results indicate that Mo not only promotes the activity of CuO/gamma-Al2O3 for the oxidative decomposition of (CH3)(2)S-2, but also enhances resistance to deactivation by sulfur compounds. The formation of Cu3Mo2O9 and CuMoO4, as confirmed by XRD, TPR and XPS analyses, plays a prominent role in the catalyst activity. Such a formation markedly enhances the catalytic activity when the added amount of Mo is not too large. However, the activity declines when the content of Mo exceeds 10 wt%. Furthermore, NH3-TPD demonstrates that adding of Mo to CuO/gamma-Al2O3 elevates the catalyst＇s acidity and acidic strength.