The purpose of the present study is to evaluate left and right atrial volume in patients with paroxysmal atrial fibrillation (PAF) and to select the best clinical variables to predict the occurrence of PAF. 157 patients and 106 normal subjects were enrolled. In patients with PAF, right atrial volume and dimension were all significantly greater (P<0.001 approximately 0.05). Left atrial (LA) volume were obviously higher (P<0.01) before correction for age. Atrial dilation and right atrial shape remoding are evident compared to normal controls. Patients are more prone to PAF occurrence if they have increased LA anterior-posterior diameter, greater P maximum and advancing age.