<jats:title>Abstract</jats:title><jats:p>A phytochemical investigation on bulbs of <jats:italic>Lycoris radiata</jats:italic> resulted in the isolation of three new Amaryllidaceae alkaloids, named 5,6‐dehydrodihydrolycorine (<jats:bold>1</jats:bold>), 6<jats:italic>β</jats:italic>‐acetoxycrinamine (<jats:bold>2</jats:bold>), and (+)‐8‐<jats:italic>O</jats:italic>‐acetylhomolycorine <jats:italic>α</jats:italic>‐<jats:italic>N</jats:italic>‐oxide (<jats:bold>3</jats:bold>), together with eleven known alkaloids, <jats:bold>4</jats:bold>–<jats:bold>14</jats:bold>. 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 <jats:bold>2</jats:bold> showed cytotoxicity against HL‐60, A‐549, and MCF‐7 cells, with <jats:italic>IC</jats:italic><jats:sub>50</jats:sub> values of 8.1, 24.3, and 15.0 μ<jats:sc>M</jats:sc>, respectively.