Objective To establish the model of sudden death in mice with mild viral myocarditis . Methods Mild viral myocarditis model was produced in Balb/c mice by Coxsackie virus B 3. Fatal ventricular arrhythmias in mice with myocarditis were induced by giving mice a small amount of aconitine. Results Mild viral myocarditis model was successfully produced in mice.The rate of ventricular arrhythmias caused by aconitine increased (from 33%,64% to 89%) with the decrease (HRD from 28~36 min -1 ,17~25 min -1 to 8~13 min -1 ) of heart rate dispersion in mice with myocarditis. Conclusion Mild viral myocarditis model is successfully established in mice.The interplay of unstability of myocardial electrophysiology and transient risk factor may be responsible for sudden death in mice with mild viral myocarditis.