Objective To explore the comparative effects of the application of ECG characteristic P-wave in PICC tip alignment. Methods Totals of 136 patients who needed PICC intubation were randomly divided into the experimental group and the control group, with 68 cases in each group. In the experimental group,after the PICC was successfully delivered to the right sternoclavicular joint, the ECG monitor was connected and based on the changes of P-wave on ECG to determine the optimum position of the end of catheter. In the control group,after the PICC was successfully delivered tothe predictive position, patients were sent to the Radiology Department to receive X-ray and located to the optimum position. The alignment accuracy rate, intervention time, costs, the predictive position and practical position, and general information were compared. Results The alignment accuracy rate in the experimental group was 94. 1%, which had no significant difference (χ2 =2. 318,P>0. 05). The intervention time and cost of the experimental group were (3. 16 ± 1.57) min and (7.12 ±0.56) yuan, which were significantly different from those in the control group (t=8. 819,27. 336;P < 0. 05 ). The results of general information and the predictive position and practical positionhad no significant difference (P>0. 05). Conclusions ECG alignment is accurate, time-saving and with low costs and it can avoid the radiation harm for nurses and patients in X-ray alignment. ECG alignment can replace the traditional X-ray alignment and become another alignment method for PICC intubation in clinical application.