Eighteen SD rats with streptozotocin-induced diabetes were observed for the influence of magnesium in glycolytic pathway in their retinal tissue.The diabetic rats were divided into 3 groups:6 of them drank 0.5% Mgso4 solution every day,6 received intramuscular Mgso4 (0.05/kg)in half month interval,and the another 6 drank tape water every day.Six normal rats were employed as employed as nondiabetic control.The activity of the three crucial rate-limiting enzymes ralating to glycolytic pathway-hexokinase,phosphofructokinase and pyruvate kinase in retinal tissue of the rats was investigated after a period of 30days.The results revealed that the levels of the enzymes were significantly depressed in diabetic rats not taking magnesium,while the enzyme levels maintained nearly the same in diabetic rats taking magnesium,while the enzyme levels maintained nearly the same in diabetic rats taking magnesium as in the control group.This suggested that the glycolytic pathway in retinal tissue was disturbed in early stage of diabtes,and magnesium might play an important role in maintaining the normal metabolism of glucose. （Chin J Ocul Fundus Dis,1993,9:81-83）