We observed the changes of plasma endothelin, hemodynamic and electrocardiogram in twelve patients undergone upper abdominal surgery under epidural anesthesia. The results showed that mean artery pressure, heart rate, cardiac output, cardiac index, systemic vascular resistance, maximum left atrial pressure, maximum ascendant speed of artery systolic pressure and mean ascendant speed of artery systolic pressure were all significantly lower during intraab-dominal exploration than that of preanesthesia (P < 0.01). Mean artery pressure and systemic vascualr resistance kept low levels to the end of operation. Plasma endothelin was significantly higher at 1 hour after skin resection than that of preanesthesia (P < 0.01) and was apparently negative related with cardiac output(CO) and cardiac index(CI) during exploration(CO r = -0.9221; CI r = -0.8768), two patients' with myocardial ischemia were specially higher. We conclude that plasma endothelin is closely related with cardiac function and myocardial ischemia during operation.