Abstract: Objective: To investigate the effects and safeties of various agents in treatment on paroxysmal atrial fibrillation in the elderly above 75years old. Methods: 264in-patients aged 75~91years old (male 185and female 79) with atrial fibrillation of less 7days were selected for this study. 611times of atrial fibrillation were recorded,but 130times (22. 3%) of atrial fibrillation were auto-converted to sinus rhythm. The rest 481times of atrial fibrillation were randomly divided into six groups for observation of rhythm conversion and rate control. Results: The cardioversion rate for atrial fibrillation were 7%,46. 9%, 71. 7%,55. 8%,32. 7% and 73. 6% in group control,digitalis,amiodarone,propafenone,verapamil and quinidin respectively. Ventricular rate control were 4%,83. 6%,84. 9%,77. 9%,78. 8%and 11. 3%in those groups respectively. The total effective rate was the highest in groups amiodarone and digitalis. When the ventricular rate was controlled fewer than90beats per minute,the patients would complain of slighter or no discomfort. No severe side effects were found in each group. Conclusion: The auto-conversion rate of paroxysmal atrial fibrillation was higher in the elderly above 75years old within the first 24hours after onset of atrial fibrillation. For treatment of paroxysmal atrial fibrillation in the elderly rate control should be the basic aim and rhythm control should be the ideal aim. Amiodarone and digitalis were agents of choicein this study.