Objective To probe into the significance of applying dynamic electrocardiogram in the clinical diagnosis of heart diseases in children.Method 54cases of children aged 4～14years with chief complaint of precordial discomfort hospitalized in our hospital from 2007to 2010were selected.They were examined using general electrocardiogram（ECG）and their heart rate change

incidence time

times and nature of arrhythmia

and change in ST-T under normal living conditions were continuously monitored within 24husing dynamic electrocardiogram（Holter）

and the results were statistically analyzed.Results 15cases detected were abnormal under general ECG

which accounted for 27.78%;42cases detected were abnormal using Holter accounting for 77.78%

which included 2cases with frequent ventricular premature beat

2cases with transient atrial tachycardia and 1case with second degree TypeⅡatrioventricular block.Differences in abnormal detection rate using ECG and Holter were statistically significant（p<0.05）.Conclusion Abnormal detection rate in Holter examination is remarkably higher than ECG

which has great clinical significance in diagnosing viral myocarditis in children

guiding drug use

and evaluating degree of myocardial damage and the outcome.