This study designed on cross- sectional base to determine electrocardiographic disorders in downsyndrome patients with congenitally normal hearts in a bid to predict fatal cardiac arrhythima in the future, to get the aim of this study the authors investegated (60) children have down syndrome without congenital abnormal hearts based on that imposible to say that All Down Syndrome patients, even in the absence of concomitant congenital heart disease should be followed up carefully by electrocardiography.