Semen Ziziphus jujuba (SZJ) has long been used in Chinese traditional medicine for the treatment of anxiety and insomnia because of its effect of decreasing monoaminergic system activity; saponins are thought to be the main bioactive factors. To investigate the sedative and hypnotic effects of saponins from SZJ, silica gel column chromatography and thin-layer chromatography were used to purify the crude extract of total saponins from SZJ. High-performance liquid chromatography showed that saponins from SZJ comprised two components, compounds I and II. Animal tests were conducted using these two compounds to compare their sedative and hypnotic effects. Results showed that both compounds had a significant effect (P < 0.05, P < 0.01) on walking time compared with that of the control group. Compound I had a significant effect on coordinated movement (P < 0.05). Both compounds prolonged the suprathreshold barbiturate induced sleeping time (P < 0.05). The number of sleeping animals increased by 30% and 20% for compounds I and II, respectively, under the subthreshold dose of sodium barbital.