Abstract: Objective To explore the improvement method of electrocardiograph connector and its clinical application effect. Methods The improved electrocardiograph connector was designed and applied in clinic according to the problems existing in unimproved electrocardiograph connector. The wear-out rate of electrocardiograph connector, the stability of electrocardiograph waveform and cathetering in place rate of peripherally inserted central catheter(PICC)tube before and after improvement were compared. Results The wear-out rate, the stability of ECG waveform and the cathetering in place rate of PICC of the improved ECG connector were better than those of unimproved electrocardiograph connector(P<0.05 or P<0.01). Conclusion The structure design of the improved electrocardiograph connector is more reasonable, and its performance is stable. The effect of the PICC tip positioning is better, and it is durable, and the feature of the machine with multiple purpose realizes the connection with many electrocardiograph equipments.