Objective To investigate the changes and significance of serum C reactive protein (CRP) and calcitonin (PCT) levels in the elderly patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).Methods One hundred and twenty elderly patients with AECOPD in the respiration deplartment of our hospital from January 2013 to study One hundred and twenty elderly patients with AECOPD in our hospital from January 2013 to June 2015 were selected to conduct the study and performed the subgroup analysis according to the BODE index (body weight,dyspnea,airflow,motor function index),times of acute exacerbation within 1 year after treatment and recurrence time,and other 40 healthy subjects in the outpatient department were selected as the control group.The serum PCT and CRP levels were compared among various groups.Results Serum CRP and PCT levels in AECOPD patients with grade 1-4 of BODE index were significantly higher than those in the control group (P＜0.05),moreover in the intra-group comparison of serum CRP and PCT,the grade l＜grade 2＜grade 3＜grade 4,the differences were statistically significant (P＜0.05).Serum CRP and PCT had the significantly positive correlation with the grades of BODE index in AECOPD patients (r=0.482,0.317,P＜0.05).After treatment,serum CRP and PCT levels in AECOPD patients with recurrence occurred more than 3 months were significantly lower than those in the patients with recurrence occurred within 3 months,the difference was statistically significant (P＜0.05);serum CRP and PCT levels in the patients with more than once recurrence at 1 year after discharge from hospital were significantly higher than those in the patients with recurrence ≤once,the difference were statistically significant (P＜0.05).Conclusion The serum levels of CRP and PCT in the patients with AECOPD can reflect dyspnea,airflow limitation and motor function ability,and conducts the preliminary assessment on the patient's prognosis.