The present invention relates to a method for treating Alzheimer's disease and 2,3-BPG metabolic disorder induced morbidities, comprising administrating a phthalide compound to an Alzheimer's disease patient or a patient having 2,3-BPG metabolic disorder induced morbidities, wherein the method is characterized by that the phthalide compound has the same effect as 2,3-BPG on modulating hemoglobin to reduce its oxygen affinity and can thus act as a 2,3-BPG functional substitute when the 2,3-BPG concentration is too low in the Alzheimer's disease patient or in the patient having 2,3-BPG metabolic disorder induced morbidities to maintain the normal oxygen release function of hemoglobin and therefore to maintain the normal cellular oxygenation level.
