A novel catalyst system composed of sodium formate and copper magnesium catalyst was developed to synthesize methanol from syngas (CO/H-2 = 1/2) in ethanol solvent at 5.0 MPa and 160 A degrees C. The pH value was found to exert an important effect on the reaction activity of the co-precipitated Cu/MgO-Na catalyst; the reaction performance of the catalyst system was also sensitively dependent on the reaction temperature in the range of 150-180 A degrees C. The successive experiment results indicated that the combination of formate species and copper catalyst should be the active site. In addition, the carbonylation step was the limiting-rate step, which was restrained by the equilibrium.