The main difficulty of TEE studying is turning two-dimensional echocardiography into a three-dimensional visual image of the heart structure, and effectively identifying each anatomical structures in echocardiography and to make accurate analysis in clinical judgment. This APP contains four TEE standard aspects, recommended by west China hospital of sichuan university. With the help of the four quadrant images user can browse 3D model diagram, ultrasonic figure and sectional drawing at the same time. Combined with the appropriate text and audio, you can get a good learning experience. This APP can be used for both teachers to teaching team, and also be used for students to review and self-study.