The preoperative measurement of adequate nail length is very important for femoral shaft fracture naiTing Operation. To reduce the disadvantages of scanography which are the fracture site pain, motion and radiation hazard, the simple external measurement method of intramedullary nail length was designated through this study. The fifty normal Korean whose bone growth v:as ceased were chosen for this study. And the lengths with the simple external measurement of thigh and scanogram of femur were compared at both side. The lateral roentgenographic view of femur was checked to analysis of anterior angulation at the proximal one third of femur was checked to analysis of anterior angulation at the proximal one third of femur. The following results were: 1. Femoral length was about 24% body height on an average. 2. The distance between the lower margin of the anterior superior iliac spine and the patellar upper pole (SPD) was equal to the distance between the tip of the greater trochanter and the cented of distal subchondral line. 3. Straight intramedullary nail length was 40 to 45 mm shorter than SPD. 4. The roentgenogram revealed that the femur took its anterior bowing by 9 degrees.