The left atrial appendage (LAA) originated from the left atrial remnant in the embryonic period. It has unique tissue structure, physiological function and hemodynamic characteristics. Its morphology and structure have great variability and are closely related to thrombosis. Real-time three-dimensional transesophageal echocardiography can fully display the three-dimensional anatomical structure of LAA, and has the function of arbitrary plane cutting of LAA images, which can comprehensively evaluate the relationship between LAA parameters and cardiac cycle. This article reviews research progress of real-time three-dimensional transesophageal echocardiography in evaluating structure and function of left atrial appendage.