This is the first report to show the preventive effects of allopurinol on AF.14 Our results complement these previous findings by demonstrating that allopurinol markedly inhibited atrial structural remodeling, increased vulnerability to AF and the expression of NF‐κB, TGF‐β, P‐p38, P‐JNK, ERK and P‐ERK, serum oxidative stress parameters (NO, XOD and MDA) as well as the abnormity of calcium homeostasis. Here, TGFB1 is linked to atrial fibrillation.