The Yellow needle crystal was isolated from Atractylis Rhizoma, having mp $124{sim}126^{circ}C$(decomp.), the chemical composition $C_{16}H_{21}N_{3}O_{6}$, and its m.w. 251. The pharmacological actions of this alkaloid were studied by various psycopharmacological experiments. 1) In order to see the effect of this Atractylis(=At.) alkaloid on gross general behaviors in mice, a behavioral analysis experiment was adapted. The occurrence number of sleep and lying in At. alkaloidal animals with the doses 10mg/kg or 20mg/kg was increased but the number of jumping, exploration, rearing and defecation was significantly decreased than those of placebo. 2) The effect of the At. alkaloid on unlearned emotional behaviors of mice was studied with an open-field method. The At. alkaloidal groups with the doses 20mg/kg or 30mg/kg showed less often the frequency of locomotion than that of placebo. 3) To know the effect of the At. alkaloid on the learning, a standard water maze experiment and conditioned avoidance response were conducted. As compared to placebo control, the aquisition rate of the maze learning in the alkaloidal mice with the dose of 10mg/kg or 20mg/kg was significantly impaired and the speed of swimming was also signficantly delayed. In the conditioned avoidance response, the extinction performances of the alkaloidal rats with doses of 20mg/kg or 30mg/kg did not differ significantly than that of placebo.