Abstract: A new compound (1) was isolated from the fermentation broth extract of marine fungal strain Cladosporium perangustum FS62 by various chromatographic methods such as silica gel,reverse silica gel,Sephadex LH20,HPLC, etc. On the basis of detailed spectroscopic analysis (HR-ESI-MS,1D NMR,2D NMR,CD),1 was elucidated as a new dimeric tetralone with the structure of (4S,4′S)-4,8,8(trihydroxy-2,3,2′,3′- tetrahydro-［4′,5-binaphthalene］-1,1′(4H,4′H)-dione,named as cladosperanol A.