Background　Visual technologies make the usually inviable structures of the body become visible by special apparatus. When it is applied by a clinician， it facilitates the promptness and precision of diagnosis and evaluation， which also can be the guidance for invasive procedures and patient treatment.　Objective　This review aimed to introduce visual technologies--the point-of-care ultrasonography， which have been widely used in anesthesiology， critical care and emergency medicine in recent years.　Content　This review introduced the backgrounds and advances of point-of-care ultrasonography.　Trend　It is predictable that as a revolutionary medical technique， visual technologies will be used more widely in daily clinical practice.