The kinetics of the hydrogen reduction of MoO3 to MoO2 and MoO2 to Mo were investigated. The results showed that the major step of the reduction of MoO3 to MoO2 was controlled by interface-chemical reaction. The apparent activation energy of this step was 58.1 Ll/mol. The major step of the reduction of MoO2 to Mo was controlled by inner diffusion. The apparent activation energy of this step was 30.1 kJ/mol.