Intravenous electrocardiograph (IVECG) can correctly positioning the catheter tip by enlarging p wave as it is moved toward right atrium, and it is a safe, reliable and accurate technique. To evaluate the efficacy of wire-conducted IVECG signal and IVECG signal from the port with sodium bicarbonate (NaHCO3) flushed catheter and to compare those with conventional anatomy landmark method was the propose of this study. This prospective study was carried out in 216 patients who suffered from malignant diseases. The correct position of the catheter tip among these groups was confirmed as follows. In group 1 (n = 80), the anatomy landmark method and portable chest radiograph recognized the correct position. In group 2 (n = 72), IVECG signal was conducted from guide wire to identify the tip position. In group 3 (n = 64), IVECG signal was conducted from the port with NaHCO3 (0.8 mEq/mL) flushed catheter to ascertain the tip position. The patient characteristics did not differ significantly among the groups. The duration of operation was significantly (P < 0.001) longer in group 1 than in group 2 and group 3 (45.4 +/- 9.3 minutes vs 35.7 +/- 8.0 minutes and 35.2 +/- 9.7 minutes, respectively). Catheter tip placement times were shorter in group 2 and group 3 than in group 1 (5.3 +/- 2.9 minutes and 6.4 +/- 3.0 minutes vs 16.7 +/- 5.7 minutes, respectively); there was a statistically significant difference between the group 1 and group 2 and group 3 (p < 0.001). Nonetheless, the duration of operation and catheter tip placement time was similar in group 2 and group 3. Early and late complications within the subsequent 3 months showed no significant difference among groups. We concluded that IVECG signal conducted from guide wire obtained a similar efficiency to that signal from the port with NaHCO3 flushed catheter on positioning the catheter tip of the venous Port-A-Cath system. It is recommended to use these methods to facilitate implanting long-term central venous devices.