Objective：To compare plasma atrial natriuretic peptide（ANP） levels in patients with different types of artial fibrillation（AF） and to analyze the related factors. Methods：The clinical data of 35 patients with paroxysmal AF，30 patients with persistent AF and 30 patients without AF were collected in this research. Baseline data，biochemical indicators，and ultrasonic cardiogram indexes were recorded. The correlation between the plasma levels of ANP in patients with different types of AF and the cardiac ultrasound indexes were analyzed. Results：At admission，the ANP levels in AF patients were significantly higher than those insinus rhythm（P<0.05），and positive correlation was observed between ANP level and their heart rates during AF（r=0.386，P=0.000）. For paroxysmal AF patients the level of ANP was significantly higher during AF than sinus rhythm（P=0.001），and positive correlation was observed between ANP level and the duration of AF（r=0.742，P=0.000）. But no correlation was shown between ANP level and the duration of AF in patients with persistent AF（r=0.386，P=0.000）. The LAD，RVDd in persistent AF patients was significantly larger than those of paroxysmal AF patients（P=0.000 vs. P=0.013） and those without AF（P=0.000 vs. P=0.023），and the LAD in paroxysmal AF group was significantly larger than that those without AF（P=0.000）. No correlation was shown between ANP level and ultrasonic cardiogram indexes of AF. Conclusion：The plasma ANP levels in AF patients are high. Notably correlation is shown between heart rates，duration of AF，and plasma ANP level. No correlation is shown between the duration of AF，ultrasonic cardiogram indexes and plasma ANP level.