Background: This study aimed to assess the role of left atrial (LA) function using strain rate (SR) imaging in predicting the maintenance sinus rhythm after pulmonary vein isolation for paroxysmal atrial fibrillation (AF) and to evaluate the impact of sinus rhythm restoration on LA structure and function. Methods and Results: Seventeen paroxysmal AF patients (M:F=13:4, mean age=55.1짹13.4 years) who underwent pulmonary vein isolation were enrolled. Echocardiographic studies including SR imaging were performed before the ablation and one month after the procedure. Mean peak systolic SR (SR-LAs), early diastolic SR (SR-LAe) and late diastolic SR (SR-LAa) were calculated by averaging the SR for each LA segments (septum, lateral, anterior, and inferior). LA reservoir index was measured as (LA end-systolic volume ��� LA end-diastolic volume) / LA end-systolic volume. Thirteen patients (76.5%) were free from AF at the one month follow-up after catheter ablation. Pre-ablation mean SR-LAe (2.59짹0.69 s^-1 vs 1.72짹0.56 s^-1, p=0.03) and SR-LAa (2.74짹0.63 s^-1 vs 1.61짹0.49 s^-1, p=0.03) were significantly higher in patients without AF recurrence compared with those of AF recurrence. However, pre-ablation LA empting fraction showed no significant difference between them. In patients with maintenance of sinus rhythm, LA volume decreased significantly at the one month follow up (24.6짹4.2 ml/m² vs 22.2짹6.5 ml/m², p=0.03). However, Mean SR-LAs, SR-LAe, SR-LAa and LA reservoir index did not change significantly after one month of ablation. Conclusions: Patients with greater SR-LAe and SR-LAa seem to have a high probability of maintaining sinus rhythm after catheter ablation of paroxysmal AF. LA strain rate may have a superior sensitivity in assessing LA abnormality compared with LA reservoir index.