The perfusion of the cat brain was performed according to the method of Ikeda, H. who modified the method of Geiger, A.. Electrocorticographical, biochemical and pharmacological findings in the case of the administration of β-OHGA were obtained, and then the correlation of their appearances were investigated. 1). Electrocorticogram of the perfused cat brain was activated by the administration of β-OH-GA. 2). Following the activation of electrocorticogram, all reflexes as conjuctival, corneal reflexes, pupillary reactions and pain sensation were activated, and then spontanous body movement appeared at the same time. 3). Cerebral blood flow rate, oxygen and glcose consumption, lactic acid liberation were all increased. 4). The changes as above were reversible and soon recovered again by the perfusion without β-OH-GA. 5). Electrocorticogram and respiration rate did not showed any alteration. And, changes of blood pressure showed different case by case and represented not determinated tendency. 6). Any significant difference between effects of threo-type and erythro-type of β-OH-GA on the perfused cat brain was not observed.