1) The oxygen consumption was studied with albino rats under normal environment after they were given Cytochrome C intravenously (10mg/kg). The cosumption was 74.6cc/kg min. with that of control, 75.4cc/kg. min. The difference of the consumptions was not statistically significant. However, under 0.5% CO environment, the oxygen consumption of the Cytochrome C treated rats (62.5cc/kg min) was significantly greater than the control (42.1cc/kg min.) 2) The recovery time of rat acutely poisoned by 1% CO was studied. The recovery time of the Cytochrome C treated group was 37.2 minutes and in control group it was 52.2 minutes. Also significant difference of fatality was noted between the treated group (21.8%) and the untreated group (49.7%) 3) The combined effects of the hyperbaric oxygenation (100% $O_2$ at 3 atmospheric pressures) and the Cytochrome C administration was compared with the effect of the simple hyperbaric oxygenation. There was no significant difference of recovery time between the experimental group while the fatality of the experiment group was lower than control group.