Abstract: 　Objective　To explore the efficacy of transesophageal atrial pacing (TEAP) in the diagnosis and treatment for infants with tachyarrhythmia. Method　The clinical data of 86 children with tachyarrhythmia under 3 years old who were treated with TEAP after ineffective drug treatment from January 2005 to December 2016 were retrospectively analyzed. Diagnosed by surface and esophageal electrocardiogram, there were 54 cases of paroxysmal supraventricular tachycardia (PSVT), 26 cases of atrial flutter (AF), 3 cases of atrial tachycardia (AT), 1 case of sinus tachycardia with Ⅰ° atrioventricular block (AVB), 1 case of junctional ectopic tachycardia and 1 case of idiopathic ventricular tachycardia (IVT). PSVT and AF children were divided into single treatment group and multiple treatment group (≥2 times) according to the times of TEAP treatment, and the differences were compared. Results　In the 86 cases (49 males and 37 females)  median age was 56 d (16.75~250.00 d). Except one case of PSVT who was proved to be sinus tachycardia withⅠ°-AVB by TEAP, 66 cases in 85 cases were successfully terminated by overspeed inhibition and the total success rate was 77.6%. The successful conversion rate was 90.7% in PSVT and 57.7% in AF. One AT and one IVT were converted to sinus rhythms successfully. In children with PSVT and AF, there was no significant difference in age, sex, ventricular rate and the proportion of underlying diseases between single treatment group and multiple treatment group (P>0.05). PSVT with cardiac insufficiency accounted for 18.5% (10/54), and AF with cardiac insufficiency accounted for 30.8% (8/26). There was no significant correlation between the successful rate of conversion and cardiac insufficiency in PSVT and AF children (P>0.05). Conclusion　TEAP is an accurate and reliable diagnosis of infant fast arrhythmia, and is an effective method for emergent and rapid termination of drug-refractory PSVT, especially for patients with cardiac insufficiency.