OBJECTIVE: To investigate the level of exhaled nitric oxide (NO) in children with asthma. METHODS: In 34 asthmatic children (aged 6～14 years) and 36 non respiratory disease subjects, exhaled NO with 13～15 cmH 2O expiratory airway pressure was measured by the chemiluminescent NO analyzer of the online method and the FEV 1 % was measured by a pocket spirometer at the same time. RESULTS: The level of exhaled NO of asthmatic children was significantly higher than that of the non respiratory disease subjects [( 89.4 ± 56.4 ) ppb vs ( 15.8 ± 5.8 ) ppb](P< 0.01 ). There was no significant correlation between exhaled NO and FEV 1% in asthmatic children (r= 0.06 ,P> 0.05 ). CONCLUSIONS: The level of exhaled NO in asthmatic children is higher than that of normal subjects.