Objective：To investigate the correlation between the expression of HMGB1 and the airway remodeling，pulmonary vascular reconstruction in COPD. Methods：24 SD rats were divided into 3 groups randomly． Healthy control group（Group A）：rats were bred for 6 weeks in normal circumstance before controlling a test later． COPD group（Group B）：200 μg LPS was instilled intratracheally once on d1 and d14 in all rats． These rats were exposed to cigarette smoke 1 h/d for 6 weeks. COPD and chronic hypoxia group （Group C）：200 μg LPS was instilled intratracheally once on d1 and d14 and the rats were exposed to cigarette smoke 1 h/d for 6 weeks． In the last 2 weeks chronic hypoxia（FiO2=0.18） 8 h/d were performed simultaneously． We studied airway wall remodeling and morphologic changes of small pulmonary arteries． The positive expression of HMGB1 in lung tissue was examined by Western blot． Results：①Compared with group A，the ratio of bronchial wall thickness over bronchial external diameter（MT％）and the ratio of bronchial wall area over total area（MA％）were significantly higher in group B&C（P<0.05）． ②The muscularization of intra-aveolar arteries in group B&C was more severe than that in group A（P<0.05）． The cross-sectional medial vascular wall area of pulmonary arteries was increased significantly in group C（P<0.05）.③Western blot showed that compared with group A，the expression of HMGB1 protein in group B&C was significantly increased（P<0.05）． The expression of HMGB1 protein in group C was higher than that of group B（P<0.05）． Conclusion：With the progression of COPD，the airway remodeling and pulmonary vascular reconstruction aggravates progressively，while the expression of HMGB1 is increased in lung tissue． There may be some relevance between the expression of HMGB1 and the airway remodeling，and pulmonary vascular reconstruction．