One new (1) and seven (2–8) known sesquiterpenoids, four dimeric tryptamine-related alkaloids (9–12) and six glycosides (13–18) were isolated from the fruits and leaves of Chimonanthus praecox (wintersweet). Based on its spectroscopic data, the new structure of compound 1, an oppositane-type sesquiterpenoid, was elucidated to be the C-4 epimer of bullatantriol (2). All isolated compounds were evaluated for their cytotoxicities against a small panel of human cancer cell lines, and only the chimonanthine-type alkaloids (10–12) were found to have cytotoxic effects against gastric carcinoma NUGC3 and hepatocarcinoma SNU739 cancer cells, with IC50 values ranging from 10.3 to 19.7 mM.