Abstract: Abstract：Objective To investigate the relationship of histone deacetylase 2 (HDAC2) and the inflammation of chronic obstructive pulmonary disease (COPD) by detecting its expression in lung tissues of COPD rats and normal rats. Methods：We made the COPD rat model by cigarette smoking. According to the time of COPD formation, we divided the rats into four groups, there were 10 rats in every group including the control group. The expression of HDAC2 protein and mRNA were detected by immunohistochemical and in situ hybridization assays. Results：The A values of HDAC2 protein and mRNA in COPD rats lung tissues were lower than that of normal rats (p<0.05). And between the COPD groups the differences were significant (p< 0.05). Conclusion：The expression of HDAC2 in COPD rats was lower than that of normal rats, and depresseded with the progression of COPD.