The effects of Diamox on the CO(2) content in the circulatory arterial blood with Dial anesthetized cats brain were measured. The experiments were performed by Van Slyke Saito method taking the blood at 9 and 24 hours respectively after the injection of Diamox. Concerning about the mean values of each 8 cases, the CO(2) content showed 11.1% and 14.1% decrease respectively than the non-injected group. These experimental results were not so sufficient for the explanation of the anticonvulsive effects of Diamox, that the author would like to give a report of the experimental results here.