Previously we reported the isolation of carinatine (1) from the bulbs of Zephyranthes carinate HERB. (Amaryllidaceae). This paper describes the isolation of a novel alkaloid clivacetine (2), as well as lycorine (3), clivatine (4), clivimine (5), and clivonine (6), from the rhizomes or the whole plant of Clivia miniata REGEL (Amaryllidaceae, Japanese name, Akabanakunshiran) and the structural assignment of 2. Clivia miniata REGEL. (Amaryllidaceae) was found to contain these alkaloids, and clivacetine was identified as O-acetoacetylclivonine (2) which has an interesting structure from a biogenetic viewpoint since it is a possible biosynthetic precursor of clivimine (5).