Abstract: There are so many stressors, like heat, effects the egg production in laying hens. Experiment was conducted in a poultry farm in Bursa. 1730 Hy-Line W77 layer aged 40 weeks assigned to caging unit were used as research materials. Hens were divided into six groups and had different amount of ascorbate supplementation; 0, 50, 100, 150, 200 and 250 mg kg-1 feed. Egg production and body weighted were recorded. As result the best ascorbate supplementation to decrease heat stress for this experiment was 100 mg kg-1 feed.