Two new steroidal alkaloids having a novel seven ring skeleton, ussurienine (1) and ussurienone (2), were isolated from the HCI-MeOH hydrolyzed alkaloid fraction of Fritillaria ussuriensis Maxim. (Ping-bei-mu). Continuous study on the same plant, however, showed that 1 and 2 were the artifacts derived from ussuriedine (3) and ussuriedinone (4), which were isolated from the free alkaloids fraction. Their structures were elucidated on the basis of spectral data, X-ray crystal analysis and chemical conversion. © 1989.