The uptake and movement of iron nanoparticles in elodea plants have been detected by the ESR method. This method is applied for the first time for the monitoring of the translocation, movement and uptake iron nanoparticles in plant organs. Exposition of stem, root or leaves of elodea in superparamagnetic iron nanoparticles (SPIONs) with concentration 12.9 mg/mL and less 10 times showed that iron nanoparticles may enter into the root tissue or cells and move to the stem and leaves. The localization and movement of iron nanoparticles depends on the exposure period and concentration.