A Mo-based catalyst (catalyst I) was prepared under microwave irradiation, and characterized with X-ray diffractometer, X-ray fluorescence spectrometry, nitrogen adsorption, Fourier transform infrared spectrometer, and scanning electron microscope. The activity of catalyst I for CO hydrogenation was studied in comparison with another Mo-based catalyst (catalyst II) prepared by conventional heating methods. The results show that CO conversion reached a maximum with temperatures up to 240 degrees C over either of the catalysts. However, CO conversion and selectivities of methanol and dimethyl ether over catalyst I were higher than those over catalyst II, indicating that microwave irradiation favors the preparation of Mo-based catalyst for CO hydrogenation catalyst.