Eight sesquiterpenes, including four guaiane-types containing an interesting epoxy unit (1–4), a rare tricyclic carbon skeleton-type (5) and three eudesmane-types (6–8), along with five known compounds, were isolated from rhizomes of Atractylodes lancea. The structures and relative configurations of 1–8 were determined by analysis of spectroscopic data, and the absolute configuration of 8 was assigned by application of the CD technique. Compounds 1, 2 and 4 were evaluated for their cytotoxic effects against P388 and A549 cells, but all were inactive. Possible biosynthetic pathways for sesquiterpenes (1–8) were discussed.