The effects of Sanjoinine-A, an alkaloid isolated from Zizyphus spinosus semens, on central nervous system and general pharmacology were studied. In summary, Sanjoinine-A depress the spontaneous locomotor activity without motor incoordination and it has slight analgesic effect. Those effects are qualitatively similar to that of diazepam but its potency is much lower than diazepam(20 times). Sanjoinine-A does not depress the electric or pentylenetetrazole induced convulsion. Those effects are dissimilar with that of diazepam. Sanjoinine-A slightly depress the spontaneous or acethylchollne induced motility of smooth muscles but degree of depressant effect was variable to tissues. Sanjoinine-A does not show any effects on digestive system, blood, kidney fuction and neural ganglion.