Abstract: Objective: To investigate the causes of sudden cardiac death(SCD) in the teenagers and to provide effective preventive measures.Methods: The autopsy pathological materials of two cases of SCD were observed and analyzed.Results: One case suffered from dilated cardiomyopathy and the other had myocarditis complicated with congenital heart disease(atrial septal defect).Conclusions: Transient and dangerous SCD is scarce in the youth,but tends to increas in recent years,which should arouse our attention.And early treatment of the primary disease is proposed.