Abstract: Objective: To investigate the locating tip accuracy of peripherally inserted center catheter(PICC) using electrocardiography(EKG) monitor in neonates.Methods: The EKG monitor in 40 neonates accorded with the PICC indications was implemented before the tube placement,the lead Ⅱ of EKG monitor was regulated to show normal EKG.The 10 ml syringe connecting with 5.5 scalp needle and heparin cap was connected to the end of PICC.The prediction length of PICC was connected with the right chest clip.The catheter tip in the superior vena cava was judged by P wave of EKG monitor,the accuracy of locating tip of PICC was judged by chest X-ray.Results: Among the 40 cases,the characteristic changes of P wave in 32 patients were identified,which was showed in the middle and low segment of superior vena cava by chest X-ray.The chest X-ray showed that 4 cases were off position,3 cases in 4 uncertainty cases were off position,and 1 case located in the lower of right atrium.The accuracy of the locating tip of PICC using EKG monitor was 92.5%.Conclusions: The characteristic P wave can judge the PICC tip locating in the middle and low segment of upper venous cavity.No characteristic P wave or uncertain judgment hint that the tube tip is heterotopia.