A water-soluble basic extract was obtained from Zizyphi spinosi semen and tested on its sedative and psychotropic activities. In a 2.2m $ imes$ 2.2m $ imes$ 0.8m open-field, the effect of the extract on unlearned emotional responses of mice was determined. Intraperitoneal injection of 5mg/kg, 10mg/kg, and 20mg/kg of the extract caused to show less often the frequency of ambulation, rearing and exploration and more the frequency of lying and sleeping than that of placebo control, meprobamate and chlordiazepoxide treated groups. In a standard shuttle box, the effect of the extract on learned emotional responses was determined. Intraperitoneal injection of 10mg/kg of the extract caused to show less conditioned response, secondary conditioned response and defecation than either placebo control or pre- and post-treated sessions with the extract throughout the acquisition and extinction of conditioned avoidance response. Intraperitoneal injection of 10mg/kg of the extract showed similar sedative actions with that of 1.25mg/kg of chlorpromazine. The extract shows major tranquilizer-like effect as chlorpromazine.