Objective:To explore the relationship between eosinophil(EOS) and IL-5,sIL-2R in asthmatic patients in sputum. Methods:Thirty asthmatic patients (asthmatic group) during exacerbation and stable stage and twenty healthy persons were selected.IL-5 and sIL-2R in sputum were determined by ELISA ,EOS apoptosis was identified by flow cytometre.Results:IL-5 ,sIL-2R and EOS apoptosis percentages in the patients during exacerbation and stable stage in sputum were increased significantly,.There were no expression of EOS apoptosis in the healthy persons. Data analyses revealed a negative correlation between EOS apoptosis and the levels of IL-5, and a closer correlation between the percentages and IL-5.Conclusion:EOS underwent apoptosis in asthmatic airway and EOS apoptosis was regulated by IL-5.There were no correlation between EOS apoptosis and sIL-2R.