Three steroidal saponins, including one new and two known compounds, were isolated from the rhizomes of Paris polyphylla Smith. One- and two-dimensional NMR, LC-MS, and interpretation of hydrolytic cleavage experiments led to the identification of the structure of the new saponin as ( 25R)-spirost-5-ene-3 beta,17 alpha-diol (pennogenin) 3- O-{ O- alpha- L-rhamnopyranosyl-(1-->2)- O-[ O- beta-xylopyranosyl-(1-->5)- alpha- L-arabinofuranosyl-(1-->4)]- beta- D-glucopyranoside}. The isolated saponins were evaluated for their antifungal activity against Cladosporium cladosporioides and Candida species and showed comparable activity to chemicals used in some commercial products.