Objective　To explore the clinical manifestations and genetic characteristics of Barth syndrome (BTHS). Method　The clinical data of BTHS in a child were retrospectively analyzed. Results　A 10-month-old boy had the main manifestations of left ventricular enlargement, fulminant myocarditis, heart failure, muscle weakness, mononucleosis, hypoglycemia, lactic acidosis, diarrhea and facial abnormalities. Gene sequencing revealed a missense mutation in TAZ gene (c.406C>T, p.Cys136Arg), which came from his mother. Conclusion　The gene mutation spectrum and clinical characteristics of BTHS in China were expanded.