Abstract: Critical care support can reduce mortality of critically ill patients. Stays in Intensive Care Units (ICU) are commonly accompanied by muscle weakness. ICU-acquired weakness could reduce patients’ body functions and quality of life. Several studies indicated that the ICU patients’ early mobility could relieve ICU acquired weakness. This article reviews the concept, ICU activity in patients with early start and pause the indications, effect, safety and early activities of the status and influencing factors.