Abstract: To study effects of addition of compound enzyme to daily diets with different levels of metabolizable energy on laying performance and blood biochemical indicators of layers, 1 440 healthy and 300-day Hy-Line brown with similar body weight and laying rate were chosen and divided into six groups randomly. Trial group 1 was as positive control with basal diets, while trial groups 3 and 5 were as negative controls with metabolizable energy reducing by 0.16 MJ/k and 0.33 MJ/kg respectively compared with the positive control, and trial groups 2, 4, and 6 were as experimental groups with addition of 400 g of compound enzyme to one ton of complete feed. The trial lasted for 45 days, and the laying performance and blood biochemical index of layers in various groups were determined at the end of the trial. Results show that the transformation rate of T lymphocyte in trial group 2 was significantly higher than that in trial group 1（P〈0.05）, but there were no significant differences between the two groups in other laying performance and blood biochemical indicators of layers（P〉0.05）; laying performance and blood biochemical indicators of layers in trial groups 4 and 6 improved significantly compared with trial groups 3 and 5（P〈0.05）. In a word, addition of compound enzyme can increase utilization rate of feed by layers and excavate potential nutrient value of feet as much as possible.