A new chromene (1) and six known compounds identified as 6-hydroxymellein (2), 6-hydroxy-5-methylmellein (3) nectriapyrone (4), chermesinone A(5), chermesinone B(6), and pomopxanthone A(7), were isolated in our investigation of the cytotoxic constituents from the fermented rice substrate of endophytic fungus Phomopsis sp. HCCB03519. The structures of these com pounds were elucidated through spectroscopic data analysis. All compounds exhibited inhibitory activities against cancer cell lines. Compound 7 showed stronger inhibition against cancer cells than the positive control 5-Fu.