MicroRNA （miRNA） is a kind of non-coding small RNA newly discovered in recent years,which function is as regulators by affecting the stability of target genes mRNA or blocking translation.miR-1 is the most abundant miR expressed in the human heart,and is closely associated with arrhythmia.Large numbers of research report show that regulating miR-1 expression levels can control arrhythmia by up-regulation or down-regulation of numerous ion channels and proteins related to cardiac electrical activity.This paper summarizes the mechanism of the regulation function of miR-1 for arrhythmia.