Background. Transesophageal echocardiography(TEE) is an advanced technique. The purpose of this article is to discuss the complication and safety of the TEE.Method. Fifteen hundred and fifty-two patients with heart disease were examined with monoplane, biplane and omniplane TEE probe(including male 727, female 825;9～76 years old). During the same period, 113 307 precordial echocardiographic examinations were performed in our laboratory. The ratio between TEE and transthoracic Echo examines was 1:73.Result.All different kinds of complication were occurred during TEE examination, including vomiting, minor mucus bleeding, laryngospasm, mandibular dislocation, angina pectoris, arrhythmia, even ventricular fibrillation and death. The article suggested that there were five steps must be improved during TEE examination including instrument and patients preparation, local anesthesia, manipulation technique and TEE probes pattern.Conclusion. Although TEE is a semiinvasive technique and can cause some kinds of complication, it is a safe technique if the five steps are improved.