Three new sesquiterpenes were isolated from the fermentation broth of Streptomyces sp. and their structures were determined as caryolane-1,7α-diol (1), 1,6,11-eudesmanetriol; (1α,6β)-form (2), 11-eudesmene-1,6-diol; (1α,6β)-form (3), together with nine known compounds as caryolane-1,9α-diol (4), 2-methyl-5-nonanol (5), soyasaponin I (6), cyclo (Ala-Leu) (7), homononatinic acid (8), β-sitosteryl glucoside-3'-O-heptadecoicate (9), 2'-deoxythymidine (10), 2'-deoxyuridine (11), trehalose (12). The structures were elucidated by spectral analysis.