One new metabolite 3,7-dimethyl-9-(-2,2,5,5-tetramethyl-1,3-dioxolan-4-yl)nona-1,6-dien-3-ol, together with nine known compounds, were isolated from the strain Xylaria sp., an endophytic fungus of Taxus mairei. Their structures were deduced from 1D and 2D NMR data. In vitro cytotoxicity and