Abstract: Blood glucose,insulin and areas under the curve （AUC） were measured and calculated during OGTT in 42 hypertensive patients and 26 control normotensive subjects. The results showed the patients had higher fasting serum insulin concentration ; higher plasma glucose, and greater area under the curve after OGTT than those of the control svbjects. But no significant difference was found in the fasting glucose between the two groups. The study indicated that there were hyperinsulinemia .glucose into1erance and insulin resistance in essential hypertensives. Captopril was used to treat hypertension effectively for 4 8 weeks. After treatment the serum insulin and glucose concentration at 1 and 2 hour postload were significantly lowered compared to pretreatment. The results suggest that insulin resistance can be ameliorated significantly by captopril in addition to their remarkable antihypertensive effect.