Key Words：Myzus persicae, artificial diet, pH value, SOD, CAT

Abstract：The effect of dietary pH on eco-physiological indices of the green peach aphid Myzus persicae (Sulzer) were investigated and the optimal pH value for artificial diets for this insect was determined.Significant differences in survival rates were observed in aphids fed diets of different pH after 3 days.The highest survival rate was recorded in aphids fed a diet with a pH of 7.0 SOD and CAT activity significantly increased in all treatments compared to the control.The antioxidant enzyme activity of aphids fed diets with pH 7.0 and 7.2 changed little, and recovered to near normal levels after 48 h.The most suitable pH for an artificial diet for the green peach aphid is 7.0.