Abstract: In this report, the technique of labelling MG-ms with ^99mTc as pertechnetate in the presence of a reducing agent such as SnCl₂ was described. The distribution of intravenously injected ^99mTc-labelled MG-ms in rabbits at different intervals of magnetic field applied and different magnetic field intensity was investigated by using an externally applied magnetic field and measuring the radioactivity at the rabbit head and other organs. When magnet was used, the radioactivity in the head, target site, was 15 times more than that when magnet was not used. At the same time, the radioactivity of the lung was 5 times less than that when magnet was not used. The newly designed magnetic field equipment was presented.