Background: Several predictors for the severity of coronavirus disease 2019 (COVID-19) have been reported. However, chronic airway inflammation characterized by accumulated lymphocytes or eosinophils may affect the pathogenesis of COVID-19. Methods: In this retrospective cohort study, we reviewed medical records of all laboratory confirmed COVID-19 patients with chronic bronchitis, chronic obstructive pulmonary disease (COPD) and asthma admitted in Sino-French New City Branch of Tongji Hospital, a large regional hospital in Wuhan, China, from January 26th to April 3rd. The Tongji Hospital ethics committee approved this study. Results: There were 59 patients with underlying chronic airway inflammation including chronic bronchitis, COPD and asthma. When compared with non-severe patients, severe patients were more likely to have decreased lymphocyte counts (0.6vs.1.1×10⁹/L, p<0.001), eosinopenia (<0.02×10⁹/L, 73%vs.24%, p<0.001), increased lactate dehydrogenase (LDH) (471.0vs.230.0 U/L, p<0.001) and elevated IL-6 level (47.4vs.5.7 pg/ml, p=0.002) on admission. Eosinopenia and elevated LDH were significantly associated with disease severity in both univariate and multivariate regression models included the above variables. Eosinopenia was also an independent risk factor for mortality of this cohort in a multivariate model included the above variables. Moreover, eosinophil counts and LDH levels tended to return to normal range over time in both groups after treatment and severe patients recovered slower than non-severe patients, especially eosinophil counts. Conclusions: Eosinopenia and elevated LDH are potential predictors of disease severity in COVID-19 patients with underlying chronic airway diseases. Theses predictors may help clinicians identify the severe COVID-19 patients with chronic bronchitis, COPD and asthma.