Objective To explore a method to reduce catheter tip malposition during PICC insertion. Methods Totally, 106 patients meeting the inclusion criteria and scheduled to receive PICC placement were evenly randomized into a control group and an intervention group according to the random number table.During PICC insertion, the patients were routinely asked to abduct the arm 90 degrees, and when the catheter tip reached the shoulder part, the control group were asked to turn the head to allow the nurse to advance the catheter, while the intervention group stayed put to allow the nurse to use the Site-Rite 5 ultrasonic probe to compress the internal jugular vein before the nurse advanced the catheter. The incidence rates of PICC malpositions were compared between the two groups. Results The total incidence rate of PICC malpositions in the intervention group was significantly lower than that of the control group （3.77% vs. 20.75%,P＜0.01）.However, no significant differences were found in the incidence rates of malposition in the internal thoracic vein, or the azygos vein, and in the rate of catheter tip folding back in the subclavian vein, between the two groups （P＞0.05 for all）. Conclusion During PICC insertion, the technique of using the Site-Rite 5 ultrasonic probe to compress the internal jugular vein before advancing the catheter could improve the rate of successful initial PICC tip placement,reduce PICC malposition into the internal jugular vein, as well as the frequency of catheter adjustment.