Abstract: Six steroidal saponins were isolated from the n-butanol extract of 90% ethanol extract of the aerial parts of Paris polyphylla var. yunnanensis by silica gel for column chromatography, MCI column chromatography and preparative high performance liquid chromatography(HPLC). According to the physicochemical properties and spectral data, they were identified as 26-O-β-D-glucopyranosyl-kryptogenin-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosy-(1→4)-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside(1), dioseptemloside G(2), polyphylloside III(3), chonglouoside SL-19(4), protodioscin(5), chonglouoside SL-5(6). Among these, compound 1 was a new compound, and compound 2 was obtained from Paris plants for the first time. The platelet aggregation activities and cytotoxicities of the above compounds were evaluated. The results showed that none of the isolated compounds showed significant platelet aggregation activity; compound 2 and 4 exhibited strong cytotoxicity against human colon adenocarcinoma cell line HT29.