Objective To investigate the role of urotensin Ⅱ(UⅡ) in the pathogenesis of asthma.Methods Lung function，differential cell count and level of UⅡin induced sputum were studied in 26 asthmatic patients in acute exacerbation and in clinical remission.Results Induced sputum UⅡ level from acute asthma was higher than that of remissed asthma [(58.88±47.38)pg/mL vs (12.69±12.78)pg/mL，Plt;0.01].Induced sputum UⅡ levels of asthma patients in acute exacerbation had a tendency to increase as disease deteriorated，which negatively correlated with FEV1% predicted (r=-0.326，Plt;0.05)，but did not with sputum total cell and neutrophil counts(Pgt;0.05).No significant difference of induced sputum UⅡ levels was found between male and female，smokers and non-smokers.Conclusion UⅡ may play a role in acute exacerbation of asthma