A strain of fungus FS86 was isolated from deep-sea sediment of South China Sea by the spread plate method. According to the culture features, morphological characteristics and ITS sequence analysis, the strain was identified as Cladosporium sphaerospermum. Bioassay results showed that the fermentation extract of the strain FS86 demonstrated significant inhibitory effects against 8 pathogenic fungi and 4 tumor cell lines with MICs of 0.1-4 mg/m L and IC50 values of 0.86-2.13 μg/m L, respectively.