Abstract: The chemical constituents of Taxus chinensis var. mairei cell cultures were investigated by chromatographic methods, including silica gel column chromatography, Sephadex LH-20 and preparative HPLC. Thirteen compounds were isolated from the 80% ethanol extract of cultured cells and their structures were elucidated by spectral data and physicochemical properties, which were identified as 2 α, 4 α, 7 β, 9 α, 10 β-pentaacetoxy-14 β-hydroxytax-11-ene (1), 2 α, 4 α, 7 β, 9 α, 10 β-pentaacetoxytax-11-ene (2), 1 β-deoxybaccatin VI (3), 2 α-acetoxytaxusin (4), taxuyunnanine C (5), yunnanxane (6), 2 α, 5 α, 10 β-triacetoxy-14 β-propionyloxy-4 (20), 11-taxadiene (7), 2 α, 5 α, 10 β-triacetoxy-14 β-isobutyryloxy-4 (20), 11-taxadiene (8), 2 α, 5 α, 10 β-triacetoxy-14 β-(2'-methyl)butyryloxy-4 (20), 11-taxadiene (9), 13-dehydroxylbaccatin III (10), 13-dehydroxy-10-deacetylbaccatin III (11), paclitaxel (12) and (13) β-sitosterol. Among them, compound 1 is a new compound, and compounds 2, 4, 10 and 11 are isolated from the cell culture of Taxus chinensis var. mairei for the first time.