The authors investigated in three experiments the blood flow (by retention of 85Sr microparticles), the 85Sr retention and state of mineralization of the tibia in female rats after oophorectomy (OOX). In the first experiment one month after OOX the retention of 85Sr microparticles is increased significantly to 158.6%, as compared with controls, the blood flow is increased insignificantly to 131.3%. In the second experiment the retention of microparticles is increased maximally 4 weeks after OOX to 152.9%, the blood flow after two weeks to 150.0%, as compared with controls; the weight of the ash per unit of bone volume of the tibia is significantly reduced after 8 weeks following OOX--to 90.8%. The two-hour retention of radioactive strontium 85Sr in the third experiment after OOX rises--significantly after 8 weeks to 133.4%. The results of the experiments are consistent with the idea on an increased metabolic activity of osseous tissue in the initial stage of the demineralization process following OOX.