Ginnol was obtained from Gingko Biloba L. by purification of its extract. Author observed the hyperventillation effect on pentobarbital anesthetized rabbit with Ginnol but there was no significant change in blood pressure. Morphine sulfate, even in large doses, did not alter the hyperventillation effect of Ginnol on rabbit. Blood chemistry of Ginnol treated rabbit showed slight increase in blood pH but within a physiological normal range, and increased total CO₂ content. While slight decreased pCO₂, increased HCO₃^- and decreased H₂CO₃ and with decreased blood Cl^- meant an uncompensatory alkalotic change but methemoglobin was not detected.