Objective To evaluate the clinical value of real-time ultrasound guided in umbilical vein catheterization. Method sA total of 60 premature infants requiring umbilical vein catheterization were chosen in this study and real-time ultrasound guided umbilical vein catheterization was performed in these infants.High frequency probe was used to measure the length of all paths to estimate the depth of duct insertion.Real-time ultrasound guided started when the top of duct placed in the intrahepatic segment of umbilical vein,then the top of duct reached the inferior vena cava not right atrium through the lateral branch of the left portal vein and venous duct.Ultrasonic scan was conducted to confirm the top of duct was inside the inferior vena cava after the duct was fastened. Results The one-time successful rate of the umbilical vein catheterization with real-time ultrasound guidance was 93.3%.The depth of duct insertion which preoperative measured by ultrasound was (7.70±0.72) cm,and the actual depth of umbilical venous catheters was (7.59±1.20) cm.There was no significant difference between these two depths (P=0.574). Conclusions The real-time ultrasound guided umbilical vein catheterization can improve the successful rate,which plays a good navigation effect.Preoperative ultrasound application can check the paths of all insertion paragraphs,and the preoperative measurement through ultrasound could guide the actual catheter.