In recent years, growing attention has been focused on the possible effect of extremely low frequency electromagnetic fields (ELF EMFs) on human reproductive health. Some epidemiological and experimental studies have suggested that ELF EMFs is associated with male infertility. However limited experimental studies have not come at an exact conclusion. Present experiments were performed on healthy adult male mice. Male reproductive effects induced by exposure of 0.2~6.4mT 50Hz ELF EMFs for 2 or 4 weeks were o...