Abstract: Objective:To investigate the clinical significance of serum cyclooxygenase-2 (COX-2) and dinoprostone concentrations variation in patients with chronic obstructive pulmonary disease (COPD) during the acute exacerbation and the stable period.Methods:Enzyme-linked immunosorbent assay was used to measure the serum concentrations of COX-2 and dinoprostone in 53 health controls and 48 patients with COPD during the acute exacerbation and the stable period.Meanwhile the serum concentration of C-reactive protein was measured in patients with COPD during the acute exacerbation.Results:The serum concentrations of COX-2 and dinoprostone in patients with COPD during the acute exacerbation and the stable period were both significantly higher than those of the control (P<0.01).The serum concentration of dinoprostone during the acute exacerbation was significantly higher than that in the stable period (P<0.01),while COX-2 did not differ significantly in the two groups;during the acute exacerbation,the serum concentrations of COX-2 and dinoprostone showed positive correlation with the concentration of C-reactive protein (P<0.01 and P<0.05),and there was also a positive correlation between COX-2 and dinoprostone concentrations (P<0.01).Conclusions:COX-2 and dinoprostone are both involved in the inflammation activity.The serum concentration of dinoprostone may help to determine the condition of COPD during the acute exacerbation.