Objective: To explore the value of inferior vena cava(IVC) in evaluating the volume state of chronic renal failure and hypertensionpatients undergoing maintenance dialysis. Methods: 56 cases of chronic renal failure and hypertensionwere included in the department of Nephrology of our hospital. Patients were divided into volume overload group and normal volume group according to CT cardiothoracic ratio. The diameter of inferior vena cava(D-IVC) was dynamically monitored by bedside ultrasound before dialysis treatment, and the variation of inferior vena cava(V-IVC) was calculated. To observe and analyze the differences between the two groups. The predictive value of each index to volume state was evaluated by ReceiverSoperatingScharacteristic(ROC) curve, and the correlation between End expiratory of D-IVC(D-IVCe) and CT cardiothoracic ratio was analyzed. Results there were higher D-IVCe(P=0.005) and lower V-IVC(P=0.01) in volume overload group than in volume normal group. The threshold values of D-IVCe and V-IVC were 17.7mm and 30%, respectively. The sensitivity, specificity were 58.3% and 81.3%, 81.2% and 58.3%, respectively. The area under ROC curve was 0.719(95%CI:0.584-0.855) and 0.696(95%CI:0.554-0.838). According to the correlation analysis, there was a positive correlation between D-IVCe and CT cardiothoracic ratio(r=0.607), and a negative correlation between V-IVC and CT cardiothoracic ratio(r=-0.585). Conclusion: the ultrasonic index of inferior vena cava has a better evaluation value for the volume state of patients with chronic renal failureand maintenance dialysis.