Osteoporosis is a generalized or local metabolic bone disease characterized by the increased risk fracture, reduced bone mass and microarchitectural deterioration of bone tissue. The etiology of osteoporosis is multifactorial, where enviromental, genetic and hormonal factors modulate the risk fracture and affects bone moneral density (BMD), which is the most important predictor of osteoporotic fractures. Osteoporosis is one of the major and growing health care problem around the world, and affecting the elderly of both sexs, however women are affected five times more likely then men. Osteoporosis is generally considered to be polygenic, arising from interaction of multiple enviromental factors with polymorphic alleles at quantitative trai loci (QTL). Genetic factors play an important role not only in the regulation of BMD, but also in the regulation of bone mass, bone turnover, bone quality and other skeletal phenotypes essential to the pathogenesis of osteoporosis. Twin and family studies shown that the heritability of bone mass has been estimated range from 80-90%. However, the genetic determination of osteoporosis is difficult because several loci and candidate gene play a key role in the regulation of bone mass and in the pathogenesis of osteoporotic fractures. Mutation and variation in these genes control BMD, bone mass and bone turnover, but none of them have been replicated over all population and moreover their function is still unclear. An important aim of future work will be meeting and understanding function of these genes and how they cause osteoporosis in individual patients. When that aim will be achieved then choosing new methods of treatment and new therapeutic targets will be easier.