Post anesthesia care units (PACU) are designed to handle the utilization of the operating rooms and provide a place for postoperative patients to recover consciousness. PACU first appeared in the 1940s, prevailed in the United States in the 1950s, and expanded gradually to Canada, South Africa and other places, and were popularized in the UK and other European countries in the 1960s. PACU were developed widely in China after 1990 and expanded rapidly after the 21st century. It is now taken as an assessment indicator for evaluating hospitals. A set of management systems for PACU was gradually regulated and established, such as anesthesia record sheets, equipment and personnel training in the process of PACU development. It is currently evolving towards centralization, economization and specialization.