There is no convention or rule to select one of three cholinesterase inhibitors, i.e., donepezil (D), galantamine (G) and rivastigmine (R) for Alzheimer’s disease (AD). Therefore, in this article we will give our considerations regarding the differentiations of prescription among these three medicines based on the clinical symptoms and biological markers.In clinical points of view, prescription D is good for AD patients at mild cognitive impairment. At mild stage, when prominence of apathy, R should be prescribed and for those showing depression, anxiety, delusion, hallucination and aggressiveness, G should be prescribed. In biological points of view, with plasm brain derived neurotrophic factor (BDNF) contents and plasma cholinesterase (p-ChE) activity, we speculate that there might be critical values in both plasma BDNF contents and p-ChE activity in ADsymptoms. Therefore, we also speculate that G should be prescribedat patients with low plasma BDNF orR with high p-ChE.