To find the isometric femoral attachment location of posterior cruciate ligament, we prepared frozen cadeveric knee in warm water for about one hour and dissected. Exposing the PCL by posterior approach, five marking pins were inserted into the femoral attachment site of the PCL at its anterior-superior, posterior-superior, anterior-inferior, posterior-inferior corners and center respectively. One pin was inserted into the center of tibial attachment. Length of each bundle was measured on flexion-extension lateral radiograph. The results were as follows; 1) Anterior-superior bundle was lengthened on extension. 2) Anterior-inferior and Posterior-inferior bundles were lengthened on flexion. 3) Posterior-inferior bundle showed largest length change during flexion. 4) Central bundle showed the least length change during flexion. 5) Anterosuperior spot of the central bundle was considered as the isometric femoral location of PCL.