To investigate methods of treating atrial tachycardia by arrhythmias by biatrial pacing and assessments of efficacy． Left atrial pacing had been done in coronary sinus in 5 cases, including 4 c ases in specific electrodes of coronary vein sinus l case in ordinary ventricu lar electrode． Biatrial leads were con nected to atrial port of DDD pacemaker by a “Y” type connector ．The pacing mo de was AAT．Results: 4 coronary sinus leads were put in middle part and l in di stal part． We tested threshhold, sensitivity and impedance in operations． The follow-up time was 4-l 8 months． Biatrial pacing had an effect on 4 cases and had significant effects o n 3 cases． The effective rate was 80 percent．Conclusion:Biatrial pacing can treat atrial tachycardia arrhythmias effectively for intraatrial block．