Abstract: Objective: To compare the effects of ibutilide and amiodarone on the atrial flutter (AFL) or atrial fihllation (AF) .Methods: Twenty-seven cases with AF of AFL were randomly divided into ibutilide group(13 cases) which were injected with 1 mg ibutilide within 10 min and added 1mg if still invalid after 10 mins， and amiodarone group(14 cases) which were injected with 150 mg amiodarone within 15 mins and added 75 mg if still invalid after 10 mins.Results: The conversing time of AF or AFL of ibutilide group was shorter than that of amiodarone group(P0.05) .Eleven cases of ibutilide group and 6 cases of amiodarone group conversed sinus rhythm with 30 mins after tretament， and 3 cases and 2 cases respectively in 30 to 90 mins after treatment.The total conversing rates of two groups were 100% and 61.54% respectively and their differences was not statistically significant(P = 0.167) .Conclusions: The conversing effects of ibutilide on AF or AFL is better than that of amiodarone and the coversed time is also shorter.