Severe cardiac arrhythmias is not rare in chilaren.Because they usually induce striking disturbance of the blood dynamics,heart failure,cardiogenic shock,Adams-stokes attack or sudden death can happen in sick child,therefore they belong to pediatric emergency.Though cardioversion-defibrillation and cardiac pacemaker implantation are widely applied to clinical practice recently,antiarrhythmic drugs are still the most common treatment method at present.In this article,dose and usage,harmful reactions,indications and contraindications of common fist-aid medicines would be introduced,and some important problems in clinical use also be discussed.