Abstract: Objective To study the changes and relationship of homocysteine(Hcy) and blood lipid levels in patients with different stages of chronic obstructive pulmonary disease(COPD) and explore the role of homocysteine in COPD patients. Methods From January,2015 to June,2016,77 cases of inpatients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD),61 cases of outpatients for stable COPD,and 353 healthy volunteers were enrolled in this study.The serum Hcy,hs-CRP,blood lipid,serum creatinine(sCr),and uric acid(UA) were detected and analyzed.The correlations with the study parameters were investigated. Results There was no statistical difference in three groups with age and gender.The Hcy and hs-CRP levels were significantly higher in AECOPD and stable COPD group compared to healthy controls(Hcy:P<0.001 and P=0.034;hs-CRP:P<0.001 and P=0.028).Additionally,Hcy and hs-CRP levels in AECOPD group were higher than that of stable COPD group(P=0.040 and P=0.009).The levels of TG and TC in AECOPD group were lower compared to stable COPD group and the healthy controls(TG:P=0.017 and P=0.001;TC:P=0.002 and P<0.001).LDL-C levels in AECOPD were significantly lower compared to stable COPD group and healthy controls(both P<0.001).Furthermore,the LDL-C level in stable COPD group was significantly lower compared to healthy controls(P=0.041),but there was no statistical difference of TG,TC level(P=0.844 and P=0.093).sCr level in AECOPD group was higher than that of healthy controls(P=0.004).There was no relationship between Hcy and blood lipid,sCr,UA,hs-CRP levels both in AECOPD and stable COPD group. Conclusion The Hcy levels in patients with AECOPD increased.Some comorbidities such as cardiovascular diseases and metabolic syndrome,maybe the result of increased serum Hcy levels in COPD patients.