Internal architecture and detailed shapes of the adult pelvis and femur were studied anatomically and radiologically. The measurements of torsion and curvature of the femurs were investigated using the special pattern gauge. The pelvis and femurs were sectioned transversely into several specimens and changing patterns of the osseous column were observed for each specimen. Torsion in the calcar femorale of the femur is reversely correlated with the anteversion and plays an important dynamic role for the internal weight bearing system. Although the central part of the cervical region of the femur is architecturally a fragile part, torsion and curvature of the cervical region form a shape serving the purpose by working in a rational way. There are three groups of osseous beams gathering at the acetabulum of the pelvis. These groups of osseous beams being exposed to the load and force from the perifemoral muscle probably induce torsion of the pelvis. There is a correlation between torsion of the pelvis and the forward-opening angle of the acetabulum.