Pontential mutagenic and antimutagenic activities of four steroidal saponins from Smilax china rhizomes were investigated. These saponins did not revealed mutagneicity in the Ames and SOS umu test. For antimutagenic activity by SOS umu test, two spirostanol glycosides, dioscin and gracillin, inhibited the activity of ${eta}-galactosidase$ induced by AF-2, but their proto-type furostanol glycosides did not show this activity.