Fontan operation is still a main procedure for treatment of complex congenital heart disease, such as univentricular heart. Fontan procedure has undergone many revisions since its introduction in 1968. The earlyapplied atriumpulmonary connection has been replaced by total cavopulmonary connection. The midterm and late results of both the intraatrial lateral tunnel and extracardiac total cavopulmonary connections were compared and analyzed in this article. Extracardiac conduit is better. The Fontan circulation failure would appear at last because of nopump function of the right ventricle. Once Fontan circulation failure occurred and could not recover by medicine, heart transplantation is mandatory, but the source of donor heart is lacking. The study of mechanical cavopulmonary assist device, to “biventricularize” the univentricular Fontan circulation, has been developed, which is quite promising. Following the development of diagnostic and treatment techniques for fetal heart disease, the treatment procedure of complex congenital heart disease has been broadened in recent years, such as to prevent the severe aortic stenosis from developing into hypoplastic left heart syndrome with fetal cardiac intervention so as to increase the chance of biventricular repair, and to terminate gestation to decrease its birth rate of complex heart abnormalities, which could not be completely repaired to date.