Abstract: The effect of iron supply and different nitrogen forms(NO3--N and NH4+-N on iron nutrition in young leaves of plants and the particularly correlation between active Fe content. total Fe content and chlorophyll content, perioxidase activity,catalase activity in young leaves of corn and bean plants was studied intensivly under controlled conditions. The results showed that there was positive correlation among these parameters with the coefficierit o. 851**, 0. 796** and 0. 884** in bean plants, and 0. 976**, 0. 580* and 0. 668* in corn plants. It indicated that active Fe content, rather than total Fe content in young leaves of dicotyledon plants. could be used as an index of Fe nutritional status.