Abstract: AIM:To study the changes of the inflammatory cytokines in patients with atrial fibrillation (AF) in different periods 1 year before and after radiofrequency ablation and to examine the difference in different types of AF and the recurrence of AF. METHODS: Forty-two AF patients were enrolled. All blood plasma were collected by venipuncture before ablation and during months 1, 3, 9 and 12 of follow-up. The levels of hs-CRP and IL-6 and IL-8 were measured by ELISA and 20 normal subjects were selected as control group. RESULTS: The levels of hs-CRP, IL-6 and IL-8 in the AF group were significantly higher than those in the control group before the ablation (P<0.05). The levels of hs.CRP in the AF group declined significantly in the first month after the ablation (P<0.05) and the levels became stable in the third month (P>0.05). Changes of the levels of IL-6 and IL-8 in the AF group were significantly different before and after the ablation, increasing in the third month (P<0.05), declining in the ninth month (P<0.05) and becoming relatively stable at the twelfth month. Significant difference was seen in the changes of IL-6 and IL-8 levels after the ablation in patients with and without recurrence of AF during the third month (P<0.05) and 88% of the patients did not have recurrence thereafter. No statistically significant differences were found in the changes of IL-6, IL-8 and hs-CRP levels in patients with and without recurrence of AF at the twelfth month. CONCLUSION: The levels of inflammatory cytokines IL-6, IL-8 and hs-CRP in paroxysmal and persistent AF patients are higher than those in normal subjects before radiofrequency ablation, suggesting that inflammation plays an important role in the occurrence, development and maintenance of AF. Radiofrequency ablation exerts short-term effect on the expression of inflammatory cytokines. Long-term changes in inflammatory factors are related to the outcome of AF.