Background　Due to the decline of organ function, the elderly patients have decreased tolerance to stress response such as surgery and anesthesia. Also, their sensitivity to drug may be increased. Therefore, the perioperative medication regimen and dosage should be carefully considered.　Objective　To review the application of dexmedetomidine (Dex) in clinical anesthesia on elderly patients.　Content　Dex has the function of sedation, analgesic, anti-anxiety and inhibiting sympathetic nerve without respiratory inhibition effect. It can be safely and effectively used in the clinical anesthesia on elderly patients. But the dose of using should be reduced when it was applied to elderly patient. Strict monitoring and following the principle of individualized medication are needed.　Trend　Dex has promising prospects for clinical anesthesia in elderly patients. But the dosage and methods of drug administration need to be further investigated.