Abstract： @@ The left atrial appendage (LAA) has been considered a relatively insignificant portion of the cardiac anatomy.Because thrombi have been found to have a predilection to form within the LAA, a better understanding of the LAA is necessary. Transesophageal echocardiography (TEE) is a technique that makes clear imaging of the LAA possible, so that its shape and function can be assessed. 1 Rheumatic mitral stenosis is common in China. Due to its characteristic hemodynamics, thrombi tend to form in the LAA in patients with this condition.This study aimed to use TEE to analyze LAA flow velocity in patients with rheumatic mitral stenosis.