In early 1986, a team of medical professionals led by Professor Chen Haohui, a renowned national critical care expert, established one of the earliest intensive care units in China: the Surgical Intensive Care Unit. In July 1991, the original Surgical Intensive Care Unit moved into the new building of the Third Ward and was formally established as the Department of Critical Care Medicine (ICU). At the end of 2005, the Department of Critical Care Medicine relocated to the new Surgical Building, with 19 beds, making it the only all-private-room ICU in China at that time, equipped with advanced hardware facilities of the current era. After nearly 30 years of development, the Department of Critical Care Medicine has now become one of China's major critical care centers, serving as a clinical department integrating medical care, education, and research. It admits over 1,000 patients annually, providing strong support for the treatment of critically ill patients in the hospital. The establishment of the critical care discipline not only elevated the hospital's overall medical treatment capabilities but also marked a significant step forward in its modernization. Under the leadership of Professors Jin Qingchen and Chen Haohui, and through the continuous efforts of several generations, the Department of Critical Care Medicine at Peking University Third Hospital has become one of China's major critical care centers, functioning as a clinical department that integrates medical care, education, and research. From an initial 4 beds at its founding to the current 19 beds, and with annual patient admissions growing from 200 cases to over 1,000 cases today, it provides robust support for the treatment of critically ill patients in the hospital. The Department of Critical Care Medicine currently comprises a team of 3 specially appointed experts, 3 doctoral supervisors, 1 master's supervisor; a physician team consisting of 6 professors/chief physicians, 4 associate chief physicians, 2 attending physicians, and 6 resident physicians, as well as a nursing team of 1 associate chief nurse, 8 supervisor nurses, and over 50 well-trained nurses. The department is equipped with advanced medical devices from both domestic and international sources, including Drager ceiling pendants, ventilators such as Drager Evita XL, Servoi, and PB840, Picco monitors, Aquarius bedside hemofiltration machines, automatic cough-assist devices, infusion pump management systems, and portable ultrasound, among others. Its hardware environment and equipment currently rank among the top tier in China. Professor Chen Haohui of the Department of Critical Care Medicine has placed great emphasis on frontline clinical work throughout years of practice, frequently visiting the bedside of critically ill and complex patients for observation and treatment. Under his guidance and leadership, the Department of Surgery and the Department of Critical Care Medicine have successfully rescued numerous patients deemed extremely difficult or even hopeless to treat. Over decades, Professor Chen has accumulated extensive experience in managing complex cases and rescuing critically ill patients, enabling him to steer treatment in the correct direction amid highly intricate changes in patient conditions. In the 1980s, he reduced the mortality rate of severe pancreatitis to 20-30%. In the early 1990s, he implemented safe low-pressure ventilation for treating acute respiratory distress syndrome (ARDS), and by the late 1990s, statistics showed no deaths attributable to ventilator-induced injury or ventilator-associated pneumonia, except in cases where the underlying disease was untreatable. He also initiated in the 1990s the practice of targeting blood glucose control below 120-130 mg/dl in critically ill diabetic patients, keeping the mortality rate of critically ill patients in the department consistently lower than that reported in domestic and international literature. Professor Jin Qingchen of the Department of Critical Care Medicine has accumulated valuable clinical experience over long-term practice, particularly in techniques for tracheal intubation and central venous catheterization in complex critically ill patients, and has personally imparted these skills to younger physicians. He was also among the early proponents in China of the lung recruitment maneuver for intubated patients, significantly reducing the incidence of ventilator-associated pneumonia. In recent years, under the leadership of Directors Zhu Xi, Yao Gaiqi, and Ma Penglin, the department has vigorously pursued discipline development and talent pipeline construction, combining the introduction and cultivation of talent. Departmental efforts have been organized to compile the PUTH ICU Work Manual, ensuring standardized and efficient practice with clear guidelines. Simultaneously, the department frequently engages in domestic and international academic exchanges, closely follows international frontiers, and actively develops new projects. In recent years, several physicians have earned doctoral degrees through dedicated effort, and multiple physicians have pursued further training abroad. The department is divided into four specialized groups: 1. Critical Care Respiratory and Circulatory Group, 2. Critical Care Gastrointestinal Group, 3. Critical Care Blood Purification Group, and 4. Critical Care Infection, Coagulation, and Maternal Group. Each group carries out its work with clear objectives, plans, and systematic organization. New projects developed in recent years include: continuous high-flow veno-venous hemofiltration at the bedside; early and further goal-directed therapy for shock (EGDT, AGDT); clinical application of lung recruitment in ARDS; corticosteroid replacement therapy under stress conditions; bronchoalveolar lavage; percutaneous endoscopic gastrostomy; intracranial pressure monitoring and mild hypothermia therapy for traumatic brain injury; comprehensive management of abdominal compartment syndrome; and ECMO for severe respiratory failure. The department has also accumulated rich experience in postoperative care and management of patients undergoing liver transplantation, simultaneous pancreas-kidney transplantation, and high cervical spinal cord injury. Its capabilities in rescuing and treating various critical conditions, including various types of shock, acute respiratory distress syndrome, and multiple organ dysfunction syndrome, have reached a top-tier domestic level. Patient mortality rates are lower than those predicted by the APACHE II severity scoring system, with an average annual overall mortality rate below 5% and a mortality rate for septic shock below 10%. The department has successfully treated several patients with dysfunction of six organ systems, drawing significant attention and acclaim from the critical care community. The department has also been actively involved in major national emergencies, such as SARS, the Wenchuan earthquake, Olympic Games security support, and H1N1 influenza. At the end of 2009, it achieved the first successful treatment of a severe H1N1 influenza patient using ECMO technology, earning recognition from the field. Over the past five years, the department has published more than 50 papers, including 8 indexed in SCI, and has secured a total of 10 national, provincial, and ministerial research grants. It has also hosted multiple national training programs, which have received highly positive feedback.