This study was made to understand a hypoglycemic action of the fat soluble fraction of Panax ginseng C.A. Meyer in streptozotocin induced diabetic rats by determining the activities of several enzymes related to carbohydrate and lipid metabolism as well as several blood component levels such as glucose and ketone bodies, and non-esterified fatty acids. Albino rats (Sprague Dawley, 170-200g, 3) were injected once with 70mg streptozotocinhg body weight intraperitoneally and fed with ordinary diet for 7 days, and then the fat soluble fraction (5 mg~20 mg/day/rat) was injected intraperitoneally once a day for three days to rats having high blood glucose level over 340 mg/100ml. After a final injection of the fat soluble fraction, rats u.ere starved for 16 hours followed by the analysis of blood serum and liver enzymes. It was found that increased levels of glucose, ketone bodies and free fatty acids in streptozotocin induced rats were decreased appreciably by administration of the fat soluble fraction. However, the amount of administered fat soluble fraction did not show any significantly different hypoglycemic action. Decreased activities of glucokinase, phosphofructokinase, pyruvate kinase, 6-phosphogluconate dehydrogenase and acetyl CoA carboxylase of the liver of streptozotocin induced diabetic rats were greatly modified suggesting that a hypoglycemic action of the fat soluble fraction was also appreciable as ginseng saponin fraction. We also compared a hypoglycemic action of the fat soluble fraction prepared from American ginseng and Chinese ginseng with that of Korean pain ginseng. 핀o significant difference of the hypoglycemic activity was observed between the above ginseng fat soluble fractions, suggesting that a study of the fat soluble fraction might be one of the most interesting subjects relating to diabetic hyperglycemia in the near future.