The effects of iron supply, nitrogen forms (N0₃^-N and NH₄⁺-N) and primary-leaves-shading on reutilization efficiency of Fe in bean plants and their mechanism were studied in nutrient solutions under controlled conditions. The 59 Fe isotopic method was also used to identify the iron reutilization efficiency. The results showed that Fe deficiency could enhance Fe translocation to young leaves from roots and primary-leaves, thus increasing Fe reutilization efficiency. The plants added with NH₄⁺-N had a much higher content of active Fe, more chlorophyll in young leaves and high Fe reutilization efficiency, much better ultrastructure chloroplast than those fed with N0₃^-N, and these were true both in Fe-sufficient and deficient treatments. No chlorosis occurred in young leaves of bean plants fed with NH₄⁺-N under Fe-deficient condition. More active Fe and 6 percent enhancement in Fe reutilization efficiency were found in the primary-leaves-shading treatment, which improved Fe nutrition in young leaves of Fe-deficient plants fed with N0₃^-N. All these results demonstrated that both NH₄⁺-N and primary-leaves-shading had a beneficial effect on mcreasing Fe reutilization efficiency, improving Fe nutrition in young leaves and depressing chlorosis symptom in bean plants.