Three new rearranged prenylated C(6)-C(3) compounds, named illioliganones A, B, and C (1-3), and a new highly oxygenated seco-prezizaane-type sesquiterpene, oligandriortholactone (7), together with three known prenylated C(6)-C(3) compounds (4-6) and a known sesquiterpene lactone (8), have been isolated from the stem bark of Illicium oligandrum. The structures of 1-3 and 7 were elucidated by spectroscopic methods including 1D and 2D NMR, HRMS, and CD experiments. The absolute configuration of the 11,12-diol moiety in 2 and 3 was determined on the basis of observing the induced circular dichroism after addition of Mo(2)(OAc)(4) in DMSO solution. The anti-inflammatory and cytotoxic activities of 1-8 were evaluated.