A femoral Prosthesis Stem made from composite material is investigating to apply to real body. The purpose of this study is to propose a design method of novel composite stem. Finite element models of stem and femur have been developed by using CT images. Some design parameters of the stem have been described and the effect of mechanical properties on the femur has been also described and compared with a traditional metal stem. The evaluation procedure for the stem has been proposed and been applied to a composite stem. It is revealed that the stem made of composite is more effective than the traditional stem made of metal.