Objective    To evaluate bronchial provocation test (BPT) in diagnosis and differential diagnosis of chronic cough in infants.     Methods    Fifty infants with chronic cough

23 wheezed infants and 10 controls were included. BPT was performed and the indexes including SaO

2

Rrs

%T-PF

%V-PF and lung symptoms were recorded.     Results    Thirty-nine out of 50 infants with chronic cough were positive (78%) in BPT

while 21 out of 23 wheezed infants positive (91.3%); the controls were all negative (100%). Significant difference in SaO

2

Rrs

%T-PF

%V-PF was found in the infants positive in BPT before and after BPT. And in the infants who were

negative

only SaO

2

and Rrs were of significant difference before and after BPT.     Conclusion    BPT is of high clinic value in auxiliary diagnosis and differential diagnosis of chronic cough in infants. To judge the BPT result with comprehensive index is more stable and reliable.