The latest advance of sedation for critically ill adult patients in intensive care unit (ICU) was reviewed in order to provide certain clinical information for the ICU physicians about sedation. Guidelines, clinical research, Meta-analysis, and reviews in recent years were collected using electronic data base. Discussions included: (1) the definition of light sedation, and its effects on clinical outcome, stress, sleep and delirium; (2) light sedation strategies included: the target population, the target sedation strategy and daily sedation interruption, clinical assessment and monitoring of sedation, selection of sedative drugs, light sedation extenuation; (3) light sedation strategies and pain, agitation, delirium control bundles; (4) the problems and prospects of light sedation. Light sedation is the main principle of currently ICU sedation strategy in critically ill adult patients. Goal-directed light sedation should be considered as a routine therapy in most clinical situation, and its goal should be achieved as early as possible in the early stage of sedation. Routine use of benzodiazepines should be avoided, especially in patients with or at a risk of delirium. Prevention and treatment of agitation with a combination of non-pharmacologic or pharmacologic methods; ICU specification rules for pain, agitation and delirium prevention and treatment should be made. Light sedation is the main ICU sedation strategy in adult patients now, but must be individualized for each patient.