AbstractMarine environments are unique habitats for microorganisms and represent uninvestigated areas that possess valuable resources. Fungi may also be important because they contribute to marine ecosystems as decomposers. The aims of this study were to investigate the halo-tolerance of marine-derived fungi and their enzymatic properties. Eighteen fungal strains representing 11 different species were used, which included 17 ascomycetes and a zygomycete. The majority were not affected by salinity and showed endo-glucanase (EG) and β-glucosidase (BGL) activities. Interestingly, the cellulolytic enzyme activity derived from Penicillium chrysogenum FU42 increased with salinity. To investigate whether this increase was due to an adaptation or an innate ability of the species, P. chrysogenum KCTC6933, which originated from a terrestrial environment, was used as a control, and its enzymatic properties were compared. Consequently, P. chrysogenum FU42, which was derived from the ocean, showed unique enzymatic properties that might enable the fungus to live in the ocean and contribute to the nutrient cycle in marine ecosystems.