It has now been shown that: (a) treatment with either perchloric acid or sulfuric acid of ilexol acetate in a mixture of benzene and ethanol, and (b) treatment with platinumcatalyzed hydrogen of ilexol and ilexone, affords an isomeric alcohol designated as isoilexol, which has C30H50O, m.p. 177~178°, +41.66° (acetate, C32H52O2, m.p. 226~227°, +48.92°).Furthermore, it has been shown that: (a) treatment with hydrochloric acid and glacial acetic acid of ilexol acetate affords α-amyrin acetate, and, in addition, an acetate (Acetate A), C32H52O2, m.p. 212~213°, −22.70°, which is hydrolyzed to an alcohol (Alcohol A), C30H50O, m.p. 202~203°, −35.88°; (b) treatment with sulfuric acid and glacial acetic acid of ilexol acetate and (c) treatment with hydrochloric acid and glacial acetic acid of isoilexol acetate, affords only Acetate A respectively.The infrared and ultraviolet spectra of these isomerized compounds have been measured, and the results of which are discussed.