Objective　To explore the clinical and gene characteristics of dilated cardiomyopathy in children. Method　The clinical data and gene test results of dilated cardiomyopathy in a child were analyzed and the relevant literatures were reviewed. Results　There was an 11-year-old male patient who had shortness of breath and palpitation after exercise. Color Doppler echocardiography showed enlarged left ventricle and left atrium, with left ventricular ejection fraction at 35% and left ventricular shortening fraction at 20%. The results of genetic testing found heterozygous mutations, c.2264G > A, p.Arg755His in exon 9 and c.3014A > G, p.Asp1005Gly in exon 11 of RBM20 gene in both child and mother. They were missing mutations and had not been reported before. Conclusion　The diagnosis of familial dilated cardiomyopathy in children is mainly based on clinical and genetic testing.