Objective To review the updated research progress about the application of echocardiography in resynchronization treatment of chronic heart failure patients.Data sources The data used in this review were from PubMed,published in English and using the key terms heart failure,echocardiography and cardiac resynchronization therapy.Study selection Relevant articles were reviewed and selected to address the stated purpose.Results Increasing numbers of studies have suggested the importance of echocardiography in resynchronization treatment of chronic heart failure patients.Echocardiography can evaluate atrioventricular,inter- and intra-ventricular mechanical dyssynchrony before cardiac resynchronization therapy (CRT),as a guidance to assess the optimal left ventricular (LV) pacing location,optimize the atrioventricular and interventricular delays and predict response to CRT.Conclusions Echocardiography is both non invasive and easily repeatable,and plays a crucial role in appraisal of heart synchronism,instruction of actuator placement,optimization of the device procedure,and prediction of the response to CRT.Chin Med J 2012; 125(19):3548-3555