Fractional exhaled nitric oxide (FeNO) is known to be a good marker of airway eosinophilic inflammation in bronchial asthma. Recently, serum high sensitivity C-reactive protein (hs-CRP) has been shown to be also useful to detect the airway inflammation.Newly diagnosed 90 cough variant asthma and 92 bronchial asthma patients were enrolled. FeNO, serum hs-CRP, pulmonary function tests, bronchial hyperresponsiveness, IgE and sputum eosinophils ratio were compared. Ninety healthy control subjects were set for FeNO and serum hs-CRP normal range reference. We have compared the clinical utilities of FeNO and serum hs-CRP to differentiate bronchial asthma and cough variant asthma.FeNO was significantly higher in bronchial asthma (92.6±85.5ppb) than in cough variant asthma (35.6±43.3; p<0.001) and both were significantly higher than normal range (18.0±6.4, p<0.001, respectively), and in differentiating between the two groups showed a sensitivity of 0.69 and a specificity of 0.73 at the cutoff value of 28ppb. Serum hs-CRP did not differ significantly between bronchial asthma (723±1162ng/ml) and cough variant asthma (558±758) even if both were significantly higher than normal range (345±401, p<0.01 and p<0.05 respectively).FeNO is more useful than serum hs-CRP in differentiating patients with bronchial asthma from those with cough variant asthma, and healthy persons.