Two new transformed sesquiterpenes of alantolactone by Mucor polymorphosporus were obtained. They were characterized as 3beta-hydroxy-11betaH-eudesm-5-en-8beta,12-olide (2) and 3beta,11alpha-dihydroxy-eudesm-5-en-8beta,12-olide (3), on the basis of spectral methods including 2D NMR. And product 3 was an unusual hydroxylation derivative of alantolactone at C-11.