Based on the fact that low temperature can reduce the oxygen consumption and metabolism of detached tissues, for preserving their viability before revascularization, we designed a computer-controlled surface cooling system, which can maintain a planned low temperature in the skin grafts, and the temperature recovers gradually with the revascularization of the grafts. The experiments on rabbits demonstrated that the temperature difference between the epidermic side and recipient-side was 6-8 degrees C when the surface cooling temperature was maintained at 20 degrees C. No significant adverse effects on the process of revascularization were observed. In three out of 4 patients, he flaps with subcutaneous fat reaching 7-9 mm. in thickness, survived.