Abstract: Objective To explore the role of single nostril deep breathing combined with anterior segment drift of catheter in the prevention of primary catheter heterotopia of peripherally inserted central catheter（PICC）by peripheral venipuncture. Methods A total of 166 patients with tumors treated by PICC were divided into a control group（n=85）and an experimental group（n=81）.Head-turning catheterization was used in the control group,while in the experimental group,single nostril deep breathing combined with anterior drift of catheter was used for catheterization.The incidence of primary catheter heterotopia was compared between the two groups. Results The incidence of primary catheter heterotopia in the experimental group was significantly lower than that in the control group（3.70% vs.15.29%,P＜0.05）.Conclusions Single nostril deep breathing combined with anterior drift of catheter can prevent the occurrence of catheter heterotopia of PICC and improve the success rate of catheterization.It is worthy of promotion in clinical practice.