A single ventricle (SV) heart defect is a rare complex congenital cardiac malformation. We followed up the four adult patients who had SV since birth without surgical intervention and they had a good prognosis.The common ultrasound characteristics of four long-term SV survivors were investigated by reviewing their medical records and the literature, and the current treatment methods for SV patients were also reviewed. In our opinion,such patients with balanced hemodynamic condition should be followed and treated conservatively. This report aims to improve the prognosis as well as quality of life of SV patients.