Using the scanning electron microscopy the thickness of external and internal layers of compact bone of the rib as well as the structure of its cancellous bone was investigated in humans aged from 19 to 89 years. The differences of bone remodeling mechanism were found in men and women of the older age groups. In men, the gradual attenuation of osseous structures was taking place. In women, bone loss was found to be rapidly progressing due to the elimination of its structural elements (transformation of compact layer into cancellous bone and disappearance of some part of trabeculae from the latter).