Two new C-3/C-3'' biflavanones, chamaejasmenin D (1) and isochamaejasmenin B (2), were isolated from the roots of Stellera chamaejasme, together with five known biflavanones, chamaejasmenin A (3), chamaejasmenin B (4), neochamaejasmin A (5), sikokianin A (6), and chamaejasmenin C (7). Their structures were elucidated by spectroscopic methods, including 2D NMR techniques. Among these compounds, 1-3 demonstrated potent antimitotic and antifungal activity with minimum inhibitory concentration (MIC) values of 6.25, 6.25, and 3.12 microg/ml, respectively.