Objective: To explore the possible relationship between Dronedaronel and HCN channels,the effects of Dronedarone on expression of HCN mRNA and protein in neonatal rat ventricular myocytes were investigated.Methods: Neonatal rat ventricular myocytes were prepared by type Ⅱ collagenase digestion,and then collected single ventricular myocytes through differential sticking wall separation method.Groups:(1)the concentration gradient of dronedaronel :the ventricular myocytes were respectively treated with different concentrations of 0.1 umol/L,0.5 umol/L,1 umol/L,5 umol/L,10 umol/L,20 umol/L;(2)the time gradient group: the ventricular myocytes were respectively treated with 10 umol/L of dronedaronel for 1 h,6 h,12 h,24 h,48 h.The levels of HCN2 and HCN4 mRNA were determined with real-time PCR.