Objective: To report 32 cases of femur supracondylar fracture treated with retrograde interlocking inramedullary nails in elderly patients. Methods: According to the AO classification, all of 32 cases were classified as extra-articular type A. 32 cases were treated with interlocking intramedullary nail by closed insertion from intercondylar fossa of the knee. All cases accepted CPM exercise as early as possible after operation. Results: Following up 5 to 15 months, all fractures united within an average duration of 5.3 months (4-7 months). According to the Shelbourne scale, the excellent rate of the knee function was 86.3％. Conclusion: Retrograde interlocking intramedullary nail is useful alternative implant for the treatment of osteoporotic supracondylar fracture of femur, particularly of the type A fracture in the elderly population. Its merits include stable fixation,high rate of fracture union and few complications.