Abstract： Objective To evaluate clinical application of phage amplified biologically assay (PhaB) in susceptibility test of Mycobacterium tuberculosis (MTB) in sputum. Methods The drug susceptibility of MTB was detected by PhaB in 143 patients with sputum-positive pulmonary tuberculosis (PTB),and the chemotherapy regimens were adjusted according to the results of susceptibility test.Independent samples t-tests were used for comparison of means.Count numbers were compared with Chisquare test.If there were count number of 0,Fisher probabilities should be used.Results The total positive rate of PhaB was 94.4％ (135/143) with no differences between three types of PTB (x2 =1.886,P ＞ 0.05 ).The duration of testing for PhaB group was (6.6 ± 1.8) days,while for control was (29.4 ±8.7) days (t =29.01,P ＜ 0.01 ).Compared with control group,the 2-month negative-conversion rate (63.2％ vs.35.1％,x2 =3.989,P ＜ 0.05 ) and cure rate ( 100％ vs.78.4％,P ＜ 0.05 ) of PhaB group in type Ⅱ patients were significantly higher.But there were no differences between PhaB and control groups in type Ⅰ and Ⅲ PTB patients.Conclusion The results of PhaB drug susceptibility test can be helpful for choosing effective chemotherapy regimen for PTB patients rapidly.