Enhancement of methanol selectivity in the products of the direct selective oxidation of methane with CH4-O-2-NO in a gas-phase reaction was examined using a Cu-ZnO/SiO2 catalyst. Two types of Cu-ZnO/SiO2 catalysts were prepared with different compositions: 3:7:90 (denoted as CZS-1) and 5:5:90 (CZS-2) as the weight percent ratios of CuO:ZnO:SiO2. Both CH3OH and CH2O were observed as C-1-oxygenates at 550degreesC in the gas-phase selective oxidation of CH4 in CH4-O-2-NO without a catalyst, but then only CH3OH was observed in the presence of the CZS-1, in addition to the direct-as-phase selective oxidation of methane. The catalyst temperature was 250degreesC and the reaction pressure was 0.4 MPa. CH3OH, CO and CO2 selectivities increased and CH2O Selectivity decreased in the presence of the Cu-ZnO/SiO2, in comparison to the values in the absence of the catalyst. We, therefore, suggested that three reactions: i.e. the hydrogenation reaction of CH2O, the dissociation reaction of CH2O, and the WGSR, progressed simultaneously on the Cu-ZnO/SiO2 catalyst in CH4-O-2-NO. Since the selectivity of CH3OH did not vary during the variation of reaction temperatures from 150degreesC up to 350degreesC over the Cu-ZnO/SiO2 catalyst, we assumed that SiO2 was a favorable support to enhance the selectivity of CH3OH in a wider catalyst temperature region.