Abstract: The hypoglycemic effect of Wuyi rock tea on Wistar rats was studied. The rats were artificially induced to become diabetic by intraperitoneal injection of STZ. They were subsequently orally fed with the tea extract for 30 days. The fasting blood glucose, AUC, FPG, INS, TG, TC, LDL-C, and HDL-C of the test animals were monitored. The results showed that (a) compared with control, the treatment groups exhibited a significant inhibition on the increase of fasting blood glucose (P < 0.01); (b) no significantly different hypoglycemic effect on the rats was observed between the high-dosage tea feeding group and the metformin-administered rats; (c) the glucose tolerance of the rats fed with the tea extract was significantly improved with a sustained duration (P < 0.01); (d) significant reductions on TC and TG of the hyperglycemic rats were shown in the treatment groups as compared to control (P < 0.05 or P < 0.01); (e) INS of the treated rats was significantly increased (P < 0.01); (f) ISI was enhanced for the treated animals (P < 0.05). It was, thus, concluded that Wuyi rock tea had a significant hypoglycemic effect on the rats.