Oral carbohydrate administration tests were used to gain more insight into the ability of common carp Cyprinus Carpio to digest different sources of carbohydrates. Four carbohyd- rates were administered orally after the common carp were fasted for 24h. Blood was sampled from fish at selected time intervals from 1 to 4h. Higher blood glucose level(p<0.05) was found in fish fed on maltose. Fish fed the diet containing cellulose showed a lower glucose level. The blood glucose level of common carp peaked at 1h (373gm/dL for maltose ;81gm/dLfor celluose)and at 3h(214gm/dL for lactose;184gm/dL for agar)after the oral admin- istration of carbohydrate. The maximum blood glucose level of 373 mg/dL observed at1h period following the maltose administration was significantly different from the maximum level observed at the same period following the cellulose administration.The maximum blood glucose level of 214 mg/dL observed at 3h period following lactose administration was significantly different from the maximum level observed at same period following the agar administration. Oral maltose resulted in apersistent hyperglycemia indicative of a diabetic-like status. Lactose appeared to be poorly absorbed from the intestinal tract and did not appear to be converted into glucose and galactose.These observations are consistent with the hypothesis that certain fishes, including the Cyprinus Carpio, resemble diabetic animals by having insufficient insulin for maximum carbohydrate utilization