Gene defects may account for 50% of hypertrophic cardiomyopathy(HCM) and 35% of dilated cardiomyopathy(DCM).Pathophysiological mechanisms that implicated in HCM and DCM include defective force generation,due to mutations in sarcomeric protein genes;defective force transmission,due to mutations in cytoskeletal protein genes.Cardiac troponin C and cardiac troponin I are linked to actin and tropomyosin by cardiac troponin T,which play an important role in cardiac contractility and relaxation.Many cardiac troponin T gene mutations have been found in HCM and DCM,and study of cardiac troponin T gene mutations may help to elucidate the pathogenesis of cardiomyopathy.In this review,we focus on cardiac troponin T gene mutations in cardiomyopathy.