Abstract: Objective To evaluate efficacy and safety of two methods for gas-filled and liquid-filled balloon of Swan-Ganz catheter to locate the bronchus of pulmonary air leakage. Methods All of 38 cases with pneumothorax were randomly divided into two groups. Group A : the bronchus of pulmonary air leakage were detected by injecting gas into balloon of Swan-Ganz catheter. Group B: the bronchus of pulmonary air leakage were detected by injecting physiological saline into balloon of Swan-Ganz catheter. Results The locating success rate in Group A was 89. 5% (17/19) and Group B was 94. 7% (18/19) ( P>0. 05). The mean time of locating in Group A was (13. 3 ±4. 1) min and Group B was (9. 6 ±3. 2) min( P <0. 05).In Group A, the dislocation rate was 47.4% and adjacent bronchial compression rate was 68.4% , and was respectively higher than Group B 21. 1% and 26. 3% ( P < 0. 05). Patients in both groups were well tolerated without any obvious adverse effects. Conclusion It is a more simple, quicker, the same safe and effective to locate the broken bronchus of pneumothorax by injecting physiological saline into balloon of Swan-Ganz catheter.