Two new dimeric compounds with antitumor activity were extracted for the first time from Sophora flavescens Ait. using several chromatographic separation methods. Compound 1 (sophobikushenine) is a dimeric cytisine-type alkaloid connected by an eight-membered heterocycle ring, and compound 2 (sophobiflavanone) is a lavandulyl biflavonoid consisting of a skeleton including nitrogen atoms as heteroatoms. The structures of the two compounds were elucidated using one- and two-dimensional NMR, ECD, and HR-ESI-MS. The inhibitory effects of the new compounds against A431 and BT474 were evaluated in vitro implementing CCK-8 and scratch assays. Sophobiflavanone inhibited the growth of A431 cells with an IC50 value of 37.77 +/- 0.98 mu M and BT474 cells with an IC50 value of 38.13 +/- 0.31 mu M; further, it exhibited a strong antimigratory activity toward 4T1.