Abstract: OBJECTIVE To find whether there were airway acidification in patients with pulmonary fungal infection,in addition to find the influence of acidification level on the illness, so as to find a better way to give adjuvant therapy to patients with pneumonia. METHODS A total of 80 pulmonary fungal infection patients in our hospital respiratory medicine from Mar. 2014 to Aug. 2015 were collected. The clinical data were collected to further calculate CPIS.In the same time, patients' exhaled breath condensate (EBC) was collected to measure pH. The first time EBC from fungal pneumonia patients was collected and then patients were randomly distributed to the two groups by the different ways of sodium bicarbonate atomization inhalation.The pH scores of patients' EBC were under detection. The CPIS was under detection after atomization treatment, and the discharge prognosis of two groups was recorded. T-test was used for the mean differences comparison between groups of paired samples and two independent samples. The χ² test was used for efficient comparison. The analysis of variance was used for understanding the relation of measurement data. RESULTS The pH level of EBC for fungal pneumonia patients was lower compared with healthy controls(t=13.717,P＜0.05). In addition, there was also significantly negative correlation between pH level of EBC and CPIS(t=-11.260,P＜0.05). Sodium bicarbonate atomization inhalation once every 12 hours was better than once every 24 hours in improvement of airway acidification(t=3.922,P＜0.05)and even better for CPIS (t=-2.361,P＜0.05). CONCLUSION There were airway acidification in pulmonary fungal infection patients, and 2.5% sodium bicarbonate atomization inhalation once every 12 hours would better improve airway acidification and the antifungal effect.