The adsorption and the photoreaction of CH2I2 and CD3OD on sublimated molybdenum oxide surfaces have been studied using high-resolution electron energy loss spectroscopy combined with thermal and photoinduced desorption spectroscopy. The energy loss peaks for nu(C-H), nu(C-D), nu(C-O) and delta(CH2) are detected for CH2I2 and CD3OD adsorbed on the MoOx thin film, where the energy losses of the nu(C-H) stretch and nu(C-D) stretch are mainly caused by impact scattering. CD3OH adsorbed on the MoOx thin film surface photodesorbs as CD3OD and CD2O due to illumination by ultraviolet (UV) light. CH2I2, adsorbs on the MoOx thin film without dissociation at room temperature, but undergoes photodissociation upon illumination by UV light via the production of intermediate =CH2(a) species.