To investigate the chemical constituents from the aerial parts of Corydalis fangshanensis and the inhibitory effects on the human breast cancer cell lines (MCF-7 and MDA-MB-231).The chemical constituents of ethyl acetate and n-butanol extracts were systematically isolated and purified by multiple column chromatography.The constituents were identified by NMR (1D,2D),MS,IR,UV,etc.Seventeen compounds were obtained and identified as 7-acetyl thalifoline (1),pycnarrhine (2),corynoxidine (3),trans-isocorypalmine N-oxide (4),tetrahydropalmatine (5),tetrahydrojatrorrhizine (6),liriotulipiferine (7),isoboldine (8),(R)-N-methylcoclaurine (9),dehydroapocavidine (10),feruloylputrescine (11),xylogranatinin (12),dimethylcaffic acid (13),4-hydroxy-3-methoxycinnamyl-β-D-glucopyranoside (14),narcissin (15),syringaresinol-4-O-β-D-glucopyranoside (16),isolariciresinol-9-O-β-D-glucopyranoside (17).Compound 1 was first reported as a natural product,2-17 were obtained from Corydalis fangshanensis for the first time.The inhibitory effects assay was carried out by MTT method.Anti-tumor activities assay indicated that 2-10,13,15-17 exhibited certain inhibition on MDA-MB-231 cell lines with the IC₅₀ values of 8.00-79.99 μmol/L,and the IC₅₀ values of 2-10,16,17 for the MCF-7 cell lines were 7.29-86.91 μmol/L.