Due to the lack of the science based evidences, we explored short term exposure effects of intermediate frequency of magnetic fields (IF-MF) to the experimental animals. Male Sprague-Dawley rats (6-7 week old) were divided into 4 groups; cage-control, sham, 2 mT and 3.8 mT exposure group, respectively. IF-MF at 21 kHz was exposed to the animals under fixed conditions in an acrylic holder. Exposure was done at 1hour/day for 3 consecutive days. On the 4th day following the exposure, biochemical and hematological parameters in the blood were analyzed. We also examined the effects to the immunological functions such as cytotoxic activity and phagocytotic activity. Results indicate that there is no effects to these parameters, even high magnetic flux density (3.8 mT; 141 times higher than the reference level to general public of ICNIRP guideline 2010) was exposed to the animals.