Ultrasound has been widely used in clinical medicine for a long period. Real-time ultrasound guided vascular access also has been approved as a safe, effective, accurate technique. Under the real-time ultrasound guidance, we can increase the successful rate and decrease the complication rate of catheter insertion. It's crucial for clinical anesthesia. The sterile real-time ultrasound guidance can be applied in acute and long-term central venous catheter insertion, peripheral venous and arterial catheter cannulation. The step-by-step procedures include pre-procedural evaluation, disinfection, sterile technique, real-time ultrasound guided venipuncture, inspect the guide wire, advance and fix the catheter. In the speech, the steps, advocacy and cost effectiveness in ultrasound guidance will be introduced. The ultrasound is also used for clinical research, such position study during venipuncture and venous thrombosis after catheter insertion. The results had been employed in clinical decision making.