<p>Three new polyketides named trichbenzoisochromen A (<b>1</b>), 5,7-dihydroxy-3-methyl -2-(2-oxopropyl)naphthalene-1,4-dione (<b>2</b>) and 7-acetyl-1,3,6-trihydroxyanthracene-9,10- dione (<b>3</b>) together with six known compounds (<b>4</b>–<b>9</b>) were isolated from a sponge-derived fungus <i>Trichoderma</i> sp. SCSIO41004. The structures of three new polyketides (<b>1</b>–<b>3</b>) were determined by the extensive spectroscopic analysis, including 1D, 2D NMR and HRESIMS data. The absolute configuration of compound <b>1</b> was confirmed by the specific optical rotation value and CD spectra analyses. Compound <b>4</b> exhibited significant inhibitory activity against EV71 with the IC<sub>50</sub> value of 25.7 μM.</p
