Abstract: This study was to determine the effect of 30week treatment of metoprolol on heart rate, blood pressurel cholesterol, triglyceride, blood sugar, glucose tolerance, insulin, kalium, sodium, calcium and urine （24 h） creatinine in 37 cases with essential hypertension. The results showed that heart rate and blood pressure were decreased, natruresis was increased , sugar tolerance curve was slightly deteriorated, insulin and insulin resistance were decreased （P ＜ 0. 01 ）, and blood-lipid was of not changed （P ＜0. 05 ）.