Abstract: Pulmonic hypertension in 2 groups of Wistar rats was induced by exposing the rats to an isobaric atmosphere containing 10% O₂， and the other containing 10% O₂ with 6.5% CO₂ respectively for 8h daily for 4 weeks. The mean pulmonary arterial pressure and right ventricular pressure, right ventricular weight, blood gas analysis and pathological changs of the hearts and lungs in the rats were observed. The results showed that the pulmonic hypertension models could be established in a short time (4 weeks) ,and could mimic cor pulmonale with respiratory failure in human better than that induced by hypobaric hypoxia.