<p>Abstract This study was conducted to evaluate the effect of solution titanium dioxide and titanium oxide on antioxidant enzyme activity and some biochemical attributes of corn during 2010 growing season in the research farm of Islamic Azad University of Shahryar –Shahr-e Qhods. The experimental design was randomized complete blocks arranged in factorial with four replications. The factors were included two growing stages i.e. four leafy stage and stem elongation for titanium application and five titanium concentration and sources including control (water), titanium oxide (Bulk) and three concentrations of 0.01%, 0.02%, and 0.03% of titanium dioxide nanoparticles. Antioxidant enzymes activity, malondialdehyde and 8-hydroxyguanosine, dityrosine, protein and membrane sta- bility were assayed. The results showed that there was significant difference between growing stages regarding catalase, glutathione peroxidase, malondialdehyde, dityrosine and protein content. In addition, <strong>titanium caused an increase in antioxidant enzyme activity and decrease in malondialdehyde accumulation. I</strong>n general titanium dioxide nanoparticle (0.03%) application improved antioxidant enzymatic system<strong> and prevent lipid peroxidation </strong>in corn plants. So it can be recommended to use this material on stressed plants.</p>