Four natural products were isolated from the fermentation extract of the marine fungus Aspergillus jensenii SS5 using various column chromatographic separation techniques,and their structures were identified as epigriseofulvin (1),sterigmatocystin (2),brevianamide M (3),and meleagrin (4) by NMR,HR-ESI-MS and X single-crystal diffraction.Compounds 1-3 were obtained for the first time,and all the compound were tested for in vitro cytotoxicity by SRB assay.The results of cytotoxic activity test showed that compound 4 had inhibitory effect on human lung cancer A549 and human liver cancer Bel-7402,and compound 2 had inhibitory effect on A549.The study of the chemical composition of the marine fungus A. jensenii SS5 has some guiding significance,and two compounds were found to have good cytotoxic activity,which provides some theoretical basis for the development of active natural products of marine fungi of the genus Aspergillus.