Abstract: Capital femoral epiphyseal necrosis following the surgical treatment of congenital islocation of the hip （CDH） is believed to be secondary to mechanical forces applied between he femoral head and the acetabulum. Hence a puppy experiment was designed to simulate ncreased ressure between the femoral head and the acetabulum. Two pins were inserted through the cetabulum and distal femur respectively in each puppy and the two pins were attached to ultifunctional fixtures. With the aid of a mechanical measurement scale the forces acting irectly through the hip joint were measured. The results of the experiment indicate that the incidence and degree of femoral necrosis increased directly with the degree and time the mechanical forces applied. thus the femoral necrosis model might be of use to explore the pathogenesis of capital femoral epiphyseal necrosis following the operative treatment of CDH.