Three-point bending test was carried out to determine the femoral load-deformntion curve when the SD rats'bilateral ovariectomies were performed six months ago. Compared to stham-operated control rats,the breaking stress indicating the biomechanical propery of femoral material was significantly decreased,the maximum lood reflecting was slightly diminished.The results show:(1)the biomechanical property of ovariectomized rats femora material was significanthy impaired.(2)attributed to the superior change of geometric configuration,the biomechanical quality of femoral diaphysis has no apparently change.