<jats:title>Abstract</jats:title><jats:p>A new sesquiterpene, eremophil‐9‐ene‐11,12,13‐triol (<jats:bold>1</jats:bold>), a new oxazole, 4‐(2‐hydroxyethyl)‐5‐methyloxazole (<jats:bold>2</jats:bold>), and the two known lactones, 5′‐hydroxyalternariol (<jats:bold>3</jats:bold>) and alternariol (<jats:bold>4</jats:bold>), were isolated from the extract of <jats:italic>Phomopsis</jats:italic> sp. A240, an endophytic fungus isolated from the bark of <jats:italic>Taxus chinensis</jats:italic> var. <jats:italic>mairei.</jats:italic> The structures of the isolated compounds were determined by analyses of their spectroscopic data, as well as by comparison with literature reports. The isolated compounds were evaluated for their cytotoxic and antioxidant activities.