Abstract: The study was designed to reveal the relationship between the various biological effects of magnetic fields and iron metabolism in vivo. The osteoporosis model in SD rats was build by retinoic acid gavage, the micro-CT scan was used to identify the successfulness of modeling. Magnet treatment (6Hz, 0.4T, 2h daily) was carried out for 30 days. After the treatment, micro-CT was used to detect the bone mineral density and other related parameters of thoracic T4. The serum iron content, total iron binding capacity, serum iron saturation and binding capacity of serum unsaturated iron, as well as serum hepcidin and transferrin levels were detected.The Results showed that the treatment of retinoic acid during osteoporosis modeling can up-regulate the serum binding capacity of total iron and unsaturated iron, as well as the expression of serum transferrin mRNA in normal rats, but, no obvious regulating effects are observed on the expression of serum hepcidin mRNA and iron content in liver and spleen. These results demonstrate that the abnormal calcium metabolism may increase the iron transport and release in vivo, but there is not a subsequent increasing in iron usage, which leads to an iron overload in certain cells. After treatment of RCMF in osteoporosis models, whose serum transferrin decreased significantly, and there is a sharp down-regulated expression of liver hepcidin and transferrin mRNA in liver, but, the expression of DMT1 and FPN1 in duodenum is up-regulated significantly. These results suggest that the treatment of RCMF could accelerate the usage of iron in various cells and tissues, so as to relieve the iron overload status. So the possible mechanism underlying the treatment effects of RCMF on osteoporosis models may relate to re-distribution of iron associate proteins, acceleration of iron usage in cells and reduction the overload of iron associate proteins in cells.