In order to determine the dose-response relationship of ethanol on blood pressure and renal function, 2 doses of ethanol were intubated into albino rats. For a direct measurement of arterial blood pressure, a polyethylene catheter(PE 10) was implanted in the abdominal aorta, and the other end of the catheter was pulled out of the back of the neck. The experiment was conducted after the rats recovered from the surgery. After emptying their bladders, the rats were placed in a metabolism cage. Mean arterial pressure (MAP) was measured and arterial blood samples were collected through the catheter. Following the collection of the control urine sample, 1 ml of 10 g% (low dose), or 30 g% (high dose) of ethanol/100 g BW was intubated. 1 ml of water/100 g BW was intubated into the control group. MAP and blood samples were taken every hour, and urine samples were collected every 90 min for 3 hours. Blood alcohol concentrations reached a peak at 1 hour (low dose: 105.0±7.5, high dose: 214.7±20.2 mg%) and decreased linearly thereafter. Following alcohol ingestion, MAP began to decrease at 15 min and remained at a significantly low level thoughout the 3 hours experimental period(low dose: 112±2→102±4, high dose: 117±2→100±8 mmHg). Urine Flow increased markedly during the first 90 min of ethanol ingestion (low dose: 0.88±0.20→1.04±0.22, high dose: 0.56±0.11→1.35±0.18 ml/1.5 hr) and decreased during the second 90 min period(low dose: 0.25±0.06, high dose: 0.22±0.06 ml/1.5 hr). Urine flow of the control group decreased gradually during the experiment (0.88±0.10{\longrightarrow}0.59±0.09→0.45±0.09 ml/1.5 hr). These results indicate that the blood-pressure-lowering and diuretic effects of ethanol are dose-related: higher doses of ethanol produce a greater decrease in blood pressure and greater diuresis.