55Fe movement in plant root was analyzed by applying the real-time imaging system (VIM-micro) developed for conventional β-ray emitters coupled with the fluorescent microscope. The sensitivity of VIM-micro to the 55Fe detection was apparently higher than that of the imaging plate. Only 2 minutes of integration time allowed the clear visualization of 55Fe distribution in the root. Ten kBq/μL of 55Fe was applied to the bottom part of the root of Arabidopsis and a rice plant. Then, 60 images of the root were taken over 2 hours. In both plants, 55Fe was preferentially accumulated in the root tip area. The inactivated root, which was pre-treated either with the metabolic inhibitor or with boiling, was also prepared to evaluate the contribution of the biological activity on the 55Fe accumulation. The result indicates that the intensive accumulation of 55Fe in the root tip area of the active normal root after 30 minutes is the consequence of the biological activity. Thus, it is suggested that Fe is actively transported to the root tip area, which is the important sink tissue.