Eight new sesquiterpenes, namely, albocinnamins A−H (1−8), along with two known ones (9and10), have been isolated from the fungusAntrodiella albocinnamomea. Compound1possesses a new backbone that might be derived from cadinane-type sesquiterpene. Structures of the new compounds were elucidated by detailed spectroscopic data analysis, single-crystal X-ray diffraction, and ECD calculations. Compounds1aand1bshowed cytotoxicity against SW480 and MCF-7 cells, with IC50values ranging from 19.3 to 33.3 μM, while compound2displayed cytotoxicity against the HL-60 cell with an IC50value of 12.3 μM. In addition, compounds5and6exhibited antibacterial activity againstStaphylococcus aureuswith MIC values of 64 and 64 µg/mL, respectively.