We succeeded in observation of ferrokinetics in a plant (20 days radish) using the micron RI imaging which was previously developed in our laboratory, by improving two criteria: (i) adjustment of the iron solution for the plant’s intake; and (ii) measurement of the radioisotope, 55Fe in the course to take up solution in the plant. The accumulation of iron atoms in the plant was confirmed by the micro-PIXE and an appropriate density of iron was determined. Under an optimal condition of iron solution containing 55Fe, the ferrokinetics in the plant was investigated by use of the micron RI imaging system.