Correct rotational alignment of the femoral component is one of the most important elements in successful total knee arthroplasty. The surgical epicondylar axis is a well-known reliable landmark for a total knee arthorplasy. However, sometimes it is difficult for surgeon to define where a sulcus is, thus, hard to define a surgical epicondylar axis during a surgery. This Study evaluated the new reference of axis “Lateral Condylar Axis (LCA)” for the distal femur. The LCA is defined by the angle between the surgical epicondyalr axis and the Lateral Condylar Axis. To evaluate the consistency of this angle through ages, genders and femoral-tibia angle, this study also measured the angles between the surgical epicondylar and the anteroposterior asix and the surgical epicondylar and the posterior condaylar axis. By evaluating out the correlations and comparing the figure between measurements using the Student test, this study suggests that the Lateral Condylar Axis is a reliable landmark to properly rotate the femoral component and is easier to define during a surgery. The 59 knees out of 41 patients data was measured in 2011 – 2012.