Objective:To study the significance of mir-141 expression in COPD (chronic obstructive pulmonary diseases) mononuclear cells, and to demonstrate its effect on proliferation and apoptosis of fibroblasts Possible to ZEB1(zinc finger E-box binding homeobox 1).Methods:40 cases acute phase of COPD patients, 80 cases of stable period COPD patients and 110 normal controls in our hospital were collected. RT-PCR was used to detect mir-141 and statistical analysis. The mir-141 mimic was constructed and transfected into lung fibroblasts. The expression of mir-141 was analyzed by RT-PCR. Cell proliferation was analyzed by CCK8 and cell apoptosis was detected by flow cytometry. Targetscan was used to predict the binding site of ZEB1 and mir-141. The target relationship between ZEB1 and mir-141 was identified by RT-PCR and west blot.Results: The expression of mir-141 in mononuclear cells of acute phase of COPD and stable period of COPD was significantly higher than that of normal controls. Mir-141 levels in acute phase of COPD were significantly higher than that of stable period of COPD. Mir-141 mimic transfection significantly up-regulated the expression of mir-141, promoted cell activity and decreased cell apoptosis rate compared with the empty control group. ZEB1 and mir-141 had binding sites predicted by Targetscan database and verified by dual luciferase assays. After mir-141 mimic transfection hat, ZEB1 mRNA and protein expression were down-regulated.Conclusions: High expression of mir-141 in COPD may promote the proliferation of lung fibroblasts and inhibit apoptosis by targeting ZEB1.