Abstract: Seven nucleoside compounds were isolated from the Oenothera biennis L. by various chromatographic techniques such as Diaion HP-20, silica gel, Sephadex LH-20, MCI and semi-preparative HPLC. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as 9-(3'-carbonyl methyl)hydroxypurine (1), 1-(3'-carbonyl methyl)purine-6,8-dione (2), N-methyl-2-pyridone-5-carboxamide (3), uracil (4), uridine (5), thymidine (6) and 2'-Ο-methoxy luridine (7). Compound 1 is a new nucleoside and compounds 2-7 were newly isolated from the Oenothera biennis L. Compounds1-2 can significantly increase the viability of BEAS-2B cells induced by TGF-β1, showing potent anti-pulmonary fibrosis activity.