Abstract: We aimed to study the effects of ferritin gene overexpression and interference on growth rate in transgenic tobacco (Nicotiana tabacum L.) plants expressing soybean (Glycine max Merr ) ferritin gene (SoyFer1) and antisense tobacco ferritin gene (NtFer2). We constructed the expression vector by placing soybean ferritin cDNA and antisense ferritin cDNA under the control of the CaMV 35S promoter to replace the GUS gene of pBI121 and produced transgenic tobacco by co-cultivation of leaf disks transformed by Agrobacterium tumefaciens vector. Kanamycin resistance analysis showed most of the T1 generation of transgenic tobacco with 3:1 separate ratios; only a few had 15:1 separate ratios. Thus, approximately 1-2 copies of exogenous genes were integrated into the tobacco genome. The exogenous gene expression was examined by PCR and northern blot analyses. On comparison of growth rate between non-transformant and transgenic tobacco plants grown on MS medium containing 0 and 5 μmol.L-1 Fe2+, we observed enhanced growth of transgenic tobacco expressing soybean ferritin gene at early developmental stages, which resulted in significantly greater plant height and fresh weights than those in non-transformants and transformants expressing anti-tobacco ferritin gene. Comparison of the concentration of MDA and chlorophyll and the activity of SOD and POD between transgenic tobacco plants and non-transformants under 0 and 5 μmol.L-1 Fe2+ showed that ferritin gene overexpression decreased the concentration of MDA and increased that of chlorophyll and the activity of SOD and POD; conversely , ferritin gene underexpression increased the concentration of MDA and decreased that of chlorophy ll and the activity of SOD and POD in transgenic tobacco plants.