Linezolid is a n anti-infective drug commonly used in clinic. Considering the large difference of individual condition ， severe basic disease ，poor organ function and large variety and quantity of drugs ，standard dose of linezolid may not be suitable for all critically ill patients. This paper reviews the relevant researches on the application of linezolid in adult critically ill patients in recent years ，analyzes the pharmacokinetic characteristics of critically ill patients ，and summarizes the influence of common physiological and pathological changes in critically ill patients on drugs. When using linezolid ，the clinical comprehensive evaluation of this special group should be strengthened. In addition to appropriately reducing the drug dosage of patients with liver/ kidney function injury ，it is also necessary to consider appropriately increasing the drug dosage in other cases. After medication ，in order to avoid excessive or insufficient drug exposure ，clinical medication monitoring should be strengthened ，especially the important mean as therapeutic drug monitoring should be used well.