A phytochemical investigation on bulbs of Lycoris radiata resulted in the isolation of three new Amaryllidaceae alkaloids, named 5,6-dehydrodihydrolycorine (1), 6 beta-acetoxycrinamine (2), and (+)-8-O-acetylhomolycorine alpha-N-oxide (3), together with eleven known alkaloids, 4-14. The structures of the new alkaloids were established by means of spectroscopic methods, and the known compounds were identified by comparison of their data with those in the literature. Compound 2 showed cytotoxicity against HL-60, A-549, and MCF-7 cells, with IC(50) values of 8.1, 24.3, and 15.0 mu m, respectively.