Abstract: Objective To investigate the correlation between the expression level of fractional exhaled nitric oxide (FeNO) and allergens,peripheral blood EOS and IgE in asthmatic children and its clinical significance. Methods A retrospective analysis was performed in 79 asthmatic children admitted to Hainan Hospital of Chinese PLA General Hospital from June 2015 to June 2017. Results The FeNO level of allergic patients with 0-1 kind of allergen was lower than that of patients with ≥2 allergens,and the difference was significant (Median:15 ppb vs 9 ppb,P=0.002).Patients with dust mite allergy had higher FeNO level than non-dust mite allergic patients (Median:20 ppb vs 10 ppb,P=0.000).FeNO level had significant correlation with EOS and IgE (r=0.480,P=0.000;r=0.450,P=0.000). Conclusion FeNO is closely corelated to allergens,peripheral blood EOS,total IgE in asthmatic children,which suggests that we should take these into full account in clinical care for asthmatic children.