Objective: To study the effect of different oxygen therapies on the rats with carbon dioxide poisoning for screening out the best on-the-spot oxygen-therapy technology for treating acute carbon dioxide poisoning. Methods: The 60 healthy male Sprague Dawley rats were randomly divided into normal control group (A group), carbon dioxide poisoning group (B group), low-concentration oxygen inhalation treatment group (C group), high-concentration oxygen inhalation treatment group (D group) and hyperbaric oxygen-therapy group (E group). Various kinds of oxygen therapies were given after the contamination. The pH, partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) of arterial blood, serum troponin I (CTNI), creatine kinase (CK), glutamic-oxaloacetic transaminase (AST), gamma-glutamyl transpeptidase (GGT), blood urea nitrogen (BUN), potassium (K), sodium (Na) and chlorine (Cl) for the rats of each group were inspected. The lung and the brain tissues were taken for observing the pathological changes. Results: There is no significant difference in pH, PO2 and PCO2 among all oxygen-therapy groups (p >0.05). The levels of CTNI, CK and AST in E group are obviously lower than that in B, C and D groups (p < 0.05). The level of serum K in E group is obviously lower than that in B, C and D groups (p < 0.05). The levels of serum Na and Cl in E group are obviously higher than that in B, C and D groups (p < 0.05). The pathological change of lungs in E group is significantly better than that in C and D groups. Conclusions: We recommend that the medical units with related conditions can give the hyperbaric oxygen therapy to patients as soon as possible