To study the value of low volume ventilation in chronic obstructive lung disease (COPD) with Type II respiratory failure, 35 patients were divided into two groups at random. The tidal volume of regular volume ventilation group was 12-14 ml.kg-1 and that of low volume ventilation group was 6-8 ml.kg-1. Some indexes of airway pressures and blood gases were recorded and those of cardiovascular function were monitored continuously. The results were that compared to the normal volume ventilation group, the actual ventilation in liters per minute was lower obviously, the expiratory time longer, the incidence rate of lung barotrauma lower, peak inspiratory pressure, end-inspiratory-pressure, and internal positive-end-expiratory pressure smaller, and side-effect on hemodynamics less in the low volume group. The results suggest that low volume ventilation with permissive hypercapnia is better than normal volume ventilation in COPD.