Abstract: Objective  To compare clinical characteristics， leukocyte (WBC)， neutrophile（N%）, C-reactive protein(CRP), procalcitonin(PCT) of chronic obstructive pulmonary disease(COPD) patients with or without bronchiectasis according to High Resolution CT (HRCT) images， and to  improve the understanding of clinical characteristics of COPD patients with bronchiectasis.
Methods  A total of 132 COPD patients were selected in this study, and divided into group A(with bronchiectasis) 47 cases and group B (not merge bronchiectasis) 85 cases by the chest HRCT to compare and analyze the general conditions, arterial blood gas analysis, the WBC, N%, CRP and PCT between two groups. Meanwhile, WBC, N%, CRP, PCT and other inflammatory indicators between smoking and non-smoking patients in group A were also compared and analyzed.
Results  There was no statistically significant difference in general condition and arterial blood gas analysis between two groups(P＞0.05). The body mass index(BMI) of patients in group A was lower than that in group B, while WBC, N%, CRP, PCT and daily cough sputum volume in group A were all significantly higher than that in group B, and the differences between two groups were statistically significant(P＜0.05). Comparison of smoking patients and non-smoking patients in group A showed that WBC, N%, CRP and PCT of smoking patients were significantly higher than those in non-smoking patients, and the difference between two groups was statistically significant(P＜0.05).
Conclusion  Patients with COPD complicated with bronchiectasis have more serious infection and greater influence of smoking, which is closely related to inflammatory indicators such as WBC, CRP and PCT.PCT and CRP have certain diagnostic value in the diagnosis of COPD patients with bronchiectasis.

Key words: pulmonary disease, chronic obstructive, bronchiectasis；tomography