¹Tra Vinh University, School of Agriculture and Aquaculture, Department of Animal Science and Veterinary Medicine, 94000, VIETNAM DOI : 10.9775/kvfd.2022.27381 Oxidative stress has become a very challenging issue to animal production due to its disturbance to animal growth. Under heat stress conditions, the ability of poultry animals to combat oxidation stress is reduced; oxidative stress minimizes the concentration of globulins in plasma, thus lowering poultry"s immune status. Many researches have been conducted to solve this problem, and one of the safest solutions is the use of Polyphenols. Polyphenols are widely known as exogenous antioxidants which act as one of the cell"s first lines of defence. Th us, the findings on the intracellular antioxidant activity of polyphenol as a plant-based feed supplement, has greatly helped improve poultry antioxidant activity due to the beneficial eff ects of polyphenols in preventing damage from oxidative stress and removing excessively produced free radicals. Th is review aims to synthesize information regarding the antioxidant activity of polyphenols and their infl uence on poultry antioxidant status. Keywords : Antioxidant, Monogastric, Oxidative stress, Polyphenols