The author designed a newtype compression intramedullary locking screw with dynamic stability, which is extensively used in the hospital for femoral fracture. This locking screw was mostly satisfactory by biomechanics test compared with GK and cloverleaf type intramedullary nail, for its greater bearing capacity, stronger and harder than the later two(P<0.01). The clinical results were shown better in thirty cases and the application of it is noted for its safety .reliability and simplicity.