The flowers of Amaryllidaceae plants have not attracted much attention from phytochemists, although over 100 alkaloids have been isolated from the roots, bulbs, leaves, fruits, and seeds of these plants. Recently, Ghosal et al. reported the isolation of new alkaloidal phospholipids from the flowers of Zephyranthes flava. Previously, we reported the isolation of several new alkaloids, galanthamine N-oxide (1), sanguinine N-oxide (2), and lycoramine N-oxide (3), along with the corresponding free bases, galanthamine (4), sanguinine (5) and lycoramine (6), from Lycoris sanguinea MAXIM. We now report the isolation of a new alkaloid, hippeastrine N-oxide (7) together with sixteen known alkaloids, hippeastrine (8), galanthamine N-oxide (1), galanthamine (4), lycoramine N-oxide (3), lycoramine (6), O-methyllycorenine N-oxide (9), O-methyllycorenine (10), homolycorine N-oxide (12), homolycorine (13), O-demethyllycoramine (14), vittatine (15), tazettine (16), lycorine (17), haemanthidine (18), and O-demethylhomolycorine (19) from the fresh flowers of Lycoris radiata HERB. Furthermore, dipalmitoylphosphatidylcholine (20) and 1-palmitoyl-2-linoleoylphosphatidylcholine (21) were obtained together with methyl palmitate (22) and methyl linoleate (23) from this plant. Crude basic material extracted by a modified method of Ghosal et al. was subjected to column and preparative thin layer chromatography (PTLC) to isolate the compounds. The new compound 7 (C₁₇H₁₇NO₆) was identified as hippeastrine N-oxide by infrared (IR), proton nuclear magnetic resonance (¹H-NMR), electron impact mass spectrum (EI-MS) data, and conversion of hippeastrine (8) to its N-oxide using m-chloroperbenzoic acid (MCPBA). The structures of other compounds were determined by spectral comparisons with authentic samples, synthesis (e.g., homolycorine N-oxide (12) from homolycorine (13)), or two-dimensional nuclear Overhauser effect correlation spectroscopy (2D-NOESY) (for O-demethylhomolycorine (19)). This is the first time that the alkaloid N-oxides 7, 1, 3, 9 and 12 have been isolated from Lycoris radiata. It is interesting that the flowers of this plant contain such a variety of alkaloids, even though in small amounts.