Two novel lactones, Cephalosporolides H (1) and I (2), were isolated from the lyophilized culture broth of the marine-derived fungus, Penicillium sp. The structures were elucidated on the basis of extensive 1D- and 2D-NMR, as well as HRESI-MS spectroscopic analyses. The relative stereochemistries of the compounds were assessed by comparison of the NOESY analysis and spectral data with those in the literature.