Background　Delirium is associated with substantial morbidity in elderly hospitalized patients, while since diagnosed, the delirium has scarcely been effectively treated. Therefore, it is of great importance to prevent postoperative delirium in elderly patients who are admitted to ICU. However, currently available treatments cannot optimally prevent the development of delirium in these patients.　Objective　To review the intervention strategies to prevent the postoperative delirium in elderly critically ill patients.　Content　To prevent postoperative delirium in elder patients in ICU, some clinical study centers used pharmacological (haloperidol, atypical antipsychotics, dexmedetomidine, melatonin) or non-pharmacological (reorientation, entertainment, family support, etc) strategies. Some of the drugs not only could reduce risk of post-operative delirium, but also cause emotional, cardiac or circadian side-effects.　Trend　The use of antipsychotics and dexmedetomidine has consensus efficacy to reduce the risk of postoperative delirium in elderly critically ill patients. However, further investigations are warranted to optimize the medication to mitigate their cardiac side-effects.