The effectiveness of six chemical inducers i.e. salicylic acid, nicotinic acid, butyric acid, potassium monohydrogen phosphate (K2HPO4) and potassium dihydrogen phosphate (KH2PO4) at 2,4 and 8 mM, and ethylene (Ethiphon 40%) at 0.1%, 0.2%, and 0.4% were tested in field trials on incidence of peanut Cercospora leaf spot compared to Score fungicide as a check. All tested inducers significantly reduced peanut Cercospora leaf spot compared to non-treated control in the two successive season 2011 and 2012. Generally, ethylene at 0.4% and KH2PO4 at 8 mM gave the highest effect on reducing of peanut Cercospora leaf spot. While, butyric and nicotinic acid at 2 mM gave the highest percentage of disease severity compared to the control in the two successive season 2011 and 2012. Increasing the concentration of treatments caused increase in their reducing efficiency of diseases severity. This study indicated that, there is a correlation between induced resistance and some biochemical changes in peanut leaf tissues. Among these biochemical changes, the increase in phenol contents (free, conjugate & total phenols) and the increase in oxidative enzyme activity (peroxidase, polyphenoloxidase and catalase). In addition to increase in total free amino acids and percentage of crude protein. The obtained data clearly showed the ability of some chemical inducers to have similar efficacy near to the fungicides efficiency (Score) in reducing peanut leaf spot disease this may lead to use chemical inducers in agriculture as alternative of fungicides.