Abstract: To investigate the chemical constituents of the endophytic fungus Penicillium sp. FJ-1 of Ceriops tagal, the chemical constituents were isolated by column chromatography on silica gel and Sephadex LH-20. Their structures were elucidated on the basis of spectroscopic analysis. Their antibacterial activity was tested by paper disco diffusion method. Two compounds were isolated and identified as 7-hydroxy-deoxytalaroflavone (1), and deoxytalaroflavone (2). Compound 1 is a new compound, and compounds 1 and 2 showed weak activity against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.