It is well known that stress is an important factor, which affects poultry production. High or low ambient temperature, fasting, electric shocks and transportation are typical stressors. Stress induces physiological malfunctions followed by growth inhibition, body fat deposition, lipid peroxidation and suppression of the immune system. Under the stressful condition, the need of antioxidants believed to be increased in order to protect the body tissues. Polyphenols proved to have protective actions against cancer, heart diseases due to its antioxidant ability. However, the roles of polyphenols under stress conditions are still unclear. This work shows that green tea polyphenol could be used as a strong anti-stress agent.