Abstract: OBJECTIVE To investigate the changes of serum procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) and prealbumin (PA) in infected patients with chronic obstructive pulmonary disease with acute exacerbation (AECOPD), so as to provide reference for clinical diagnosis and treatment. METHODS A total of 80 cases of healthy persons from Jan. Aug 2014 to Dec 2015 were taken as control group, 80 cases of COPD patients in remission were taken as remission group, and 80 cases of AECOPD patients were taken as acute group. The differences of serum PCT, hs-CRP and PA of the three groups were compared. The differences of serum PCT, hs-CRP and PA between infected and uninfected patients, and patients with different grade of pulmonary function classification in acute group were compared. RESULTS Acute group had the highest content of PCT and hs-CRP, and the lowest content of PA (P<0.05). At the same time, PCT and hs-CRP levels in infected patients were significantly higher than those in uninfected patients, and PA level was significantly lower than that in uninfected patients (P<0.05). In addition, there were significant differences of serum PCT, hs-CRP and PA levels among infected patients with different grade of pulmonary function classification of acute group, in which grade Ⅲ had the highest content of PCT and hs-CRP, and the lowest content of PA(P<0.05). CONCLUSION The serum PCT and hs-CRP content are significantly increased in infected patients with AECOPD, while the PA content is significantly decreased. PCT, hs-CRP and PA have clinical significance for evaluation the patients' condition.