Abstract: AIM: To study the levels of IL-17 and IL-10 in left and right atrium serum of patients with atrial fibrillation(AF) and to investigate their relation with the progression of atrial fibrillation.METHODS: Forty-two patients with AF,including 24 paroxysmal atrial fibrillation patients and 18 persistent atrial fibrillation patients and a control group of 17 selective paroxysmal supraventricular tachycardia or pre-excitation syndrome patients were included in the study.The levels of IL-17 and IL-10 in serum from left and right atrium evaluated by ELISA and the left atrial long diameters measured by cardiac ultrasound heartbeat graph were used to study the association between IL-17 and IL-10 in serum and AF left atrial structural remodeling.RESULTS: Levels of IL-17 and IL-10 in left and right atrium serum from patients with AF were both higher than those of controls(P<0.01,P<0.01,P<0.01,P<0.05,respectively).CONCLUSION: IL-17 and IL-10 in serum are significantly related to development of AF and may play an important role in the progression of AF.