Abstract: Objective To study the relationship between serum MMP-9 and TNF-α and serum bone turnover markers in male patients with stable chronic obstructive pulmonary disease. Methods Total 90 cases of male stable chronic obstructive pulmonary disease in our hospital were enrolled into this study.Based on the results of bone mineral density tests,they were divided into osteoporosis group,low bone group and normal bone group.The levels of bone mineral density,MMP-9,TNF-α and bone turnover markers were compared and the correlation was analyzed among the three groups. Results The BMD of osteoporosis group were lower than that of low bone group and normal bone group(P<0.05),The BMD of low bone group were lower than that of normal bone group(P<0.05).Serum MMP-9 and TNF-αof osteoporosis group were higher than those of low bone group and normal bone group(P<0.05),MMP-9 and TNF-αof low bone group were lower than those of normal bone group(P<0.05).Serum sBAP and sOC of osteoporosis group and low bone group were higher than those of normal bone group(P<0.05),serum sCTX of osteoporosis Group were higher than those of low bone group and normal bone group(P<0.05).The BMD was negatively correlated with serum MMP-9(P<0.05).The BMD were positively correlated with serum sBAP(P<0.05).The BMD were positively correlated with serum sOC(P<0.05).The BMD were negatively correlated with serum sCTX(P<0.05). Conclusion The levels of serum MMP-9 and TNF-α are high in patients with chronic obstructive pulmonary disease,BMD is correlated with the levels of serum MMP-9 and TNF-α and bone turnover markers.