Bioassay-guided fractionation of the ethanol extract of the roots and rhizomes of Veratrum taliense yielded two new and thirteen known steroidal alkaloids. The structures of the two new compounds, neoverataline A and B, were established by extensive spectroscopic analyses to be 3,4-secocevane-4, 9-olid-14,15,16,20-tetra-ol-3-oic acid and 3, 4-secocevane-4, 9-olid-7, 14, 15, 16, 20-penta-ol-3-oic acid, respectively, and are a novel carbon skelton. All of the fifteen alkaloids were subjected to in vitro antifungal assays, which showed that the verazine- (veramitaline, stenophylline B, stenophylline B-3-O-b-D-glucopyranoside, veramiline-3-O-b-D glucopyranoside) and jerveratrum- type (jervine, jervine-3-O-b-D-glucopyranoside) alkaloids exhibited strong antifungal activities against the phytopathogenic fungus Phytophthora capisis with MICs of 160, 120, 160, 80, 80 and 120mg·L21, respectively. Furthermore, the verazine-type alkaloids stenophylline B, stenophylline B 3-O-b-D-glucopyranoside and veramiline 3-O-b-D-glucopyranoside were shown to also inhibit the growth of another fungal phytopathogen Rhizoctonia cerealis with MICs of 160, 120 and 120mg mL21. The MICs of triadimefon (an antifungal agrochemical used herein as a positive control) against P. capisis and R. cerealis were 120 and 80mg mL21, respectively. A preliminary structure–activity relationship regarding these alkaloids has been formulated.