The purpose of this research was to study the effect of Alendronate on bone mineral density (BMD) and markers of bone turnover in male and female Wistar rats and senescence-accelerated OXYS rats with early development of osteoporosis. The animals were treated with Alendronate (0.84 mg/kg) during 2 months from the age of 8 months. The effect of the drug depended on genotype and sex of animals. Alendronate increased the BMD and bone formation markers osteocalcin levels in the blood of female rats OXYS with low their initial level. In Wistar rats the drug increased bone mineral density only in males, while females reduced the level of osteocalcin. The level of serum calcium did not change, but its urinary excretion in Wistar male rats and in female rats of both strains was increased. The ability to influence on the development of disease by standard treatment shows that OXYS rats are suitable models to study the pathogenesis and design of new therapeutic targets of osteoporosis.