Critical lung ultrasound was originated from in France, as we know, professor Daniel A. Lichtenstein who was regarded as the father of critical lung ultrasound in the world, pushed the great development of critical lung ultrasound, concluded twelve signs of lung ultrasound, created the BLUE-protocol which allows fast causal diagnosis of acute respiratory failure, the FALLS-protocol used in acute circulatory failure without obvious causes and the SESAME-protocol used during cardiac arrest. Critical lung ultrasound as a new interdisciplinary subject, will provide more new ideas and solutions for diagnosis and treatments in critically ill patients.