This invention relates to a use of hederagenin 3-O-.alpha.-L-rhamnopyranosyl((1.fwdarw.2)-[.beta.-D-glucopyranosyl(1.fwd- arw.4)]-.alpha.-L-arabinopyranoside or a Pulsatillae radix extract containing the same as a therapeutic agent for solid tumors. Also, this invention relates to a method of preparing a therapeutic agent for solid tumors by using hederagenin 3-0-.alpha.-L-rhamnopyranosyl(1.fwdarw.2)-[.beta.-D-glucopyranosyl(1.fwda- rw.4)]-.alpha.-L-arabinopyranoside, or a method of treating a subject suffering from solid tumors, comprising administering to the subject a therapeutically effective dose of hederagenin 3-0-.alpha.-L-rhamnopyranosyl(1.fwdarw.2)-[.beta.-D-glucopyranosyl(1.fwda- rw.4)]-.alpha.-L-arabinopyranoside.