Phytochemical investigation of the ethanolextract of the bulbs of Lycoris caldwellii afforded fournew alkaloids, (?)-N-methoxylcarbonyl-nandigerine (1),(?)-N-methoxycarbonyl-lindcarpine (2), (?)-10-O-methylhernovineN-oxide (3), and (?)-3-hydroxy-anhydrolycorineN-oxide (4). Structural elucidation of all the compounds wereperformed by spectral methods such as 1D and 2D (1H-1HCOSY, HMQC, and HMBC) NMR spectroscopy, in additionto high resolution mass spectrometry. All the alkaloids werein vitro evaluated for their cytotoxic activities against eighttumor cell lines (BEN-MEN-1, CCF-STTG1, CHG-5, SHG-44, U251, BGC-823, HepG2, and SK-OV-3). Alkaloids 1and 2 exhibited particular cytotoxic activities against astrocytomaand glioma cell lines with IC50 of 9.2–11.3 lM and10.4–12.2 lM respectively.