A new method for the reduction of metal oxide catalysts has been developed, for the reduction of the CuO - ZnO - A1203 catalyst for liquid phase methanol synthesis. The reducing agent is a 5% hydrogen in nitrogen mixture and the operation is carried out at 446.09 KPa. This method makes it possible to reduce finely crushed catalyst (-100 + 120 mesh) in a three phase slurry reactor. This method offers several advantages over methods in which the catalyst is reduced in a gas-solid contact mode and then slurried for use. The catalyst has been shown to be very effectively reduced and reaches its full production capacity after reduction.