Abstract: AIM: To study the constituents and bioactivity of Illicium simonsii. METHODS: Compounds were isolated by a combination of chromatographic materials, silica gel, ODS, and Sephadex LH-20, and finally purified by preparative HPLC. Their structures were elucidated on the basis of spectroscopic methods, and they were evaluated for their cytotoxic activities by the MTT method. RESULTS: Seven compounds were obtained and were identified as veranisatin F (1), anisatin (2), (1S)-minwanenone (3), honokiol (4), macranthol (5), (+)-pinoresinol (6), and matairesinol (7). CONCLUSIONS: Compound 1 is a new seco-prezizaane-type sesquiterpene, while compounds 6 and 7 were isolated from Illicium simonsii for the first time. Compounds 2 and 3 showed strong inhibitory activities against the growth of NCI-H460 and SMMC-7721 cells comparable to 5-fluorouracil, and compound 7 to a lesser extent; the other isolates showed no cytotoxicity.