Objective To assess and review the methods of the reversed posterior interosseous artery flap for treating the contracture of the first web space. Methods Forty-two cases of the first web space severe contracture were cured by the reversed posterior interosseous artery flap rotate at 1.5-2.0 cm proximal ulnar styloid process after release the adhesion. After operation curative effects were evaluated by measuring the first web space with Gu's method. Results The flap of 42 cases obtain success, however 3 cases was partly necrosis of epidermis. Follow-up examination was obtained in 31 cases for average 18 months after operative.The width of the first web space was augmented an average of 37.9 mm. Rehabilitation training after operation can enhance the effect of the therapy with 8.6 mm more expanded. Conclusion The flap is an ideal choice for treatment on the defect of the contracture of the first web space and rehabilitation training after operation is important.