We developed a subcutaneously adjustable new pulmonary artery banding device which can be easily tightened or released in patients with unstable postoperative hemodynamics. The banding device consists of stainless spring which is enveloped with PTFE, nd polyvinyl catheter(5F). And the adjuster consists of another polyvinyl tube with forming cap. We mark transluscent polyvinyl tube 1mm each in length. 6 dogs weighing 15 to 25 kg underwent banding of descending thoracic aorta with the device. At postoperative 1 and 2 day, the device was effectively banded and released. Even 3 months later, we noted effective banding with some degree of vessel injury. The preliminary animal study suggests that this new device may be applicable in patient with excessive pulmonary blood flow.