Congenital myotonic dystrophy is an inherited, autosomal dominant disease that results in a progressive wasting of the skeletal muscle, and sometimes heart and smooth muscles in human. In the newborn period, an affected infant is profoundly weak, has difficulty in sucking and swallowing, and may have severe respiratory difficulties. Myotonia is not a feature of the condition at this stage. Motor development is usually delayed in these children, and they may show some signs of mental retardation. Generally, the condition improves through the early years but deteriorates during late childhood and adolescence, when the 'adult' features of the disease gradually emerge. The gene defect responsible for myotonic dystrophy has proved to be a region of unstable fragment of DNA on chromosome 19. An expansion of a CTG(cytosinethymine-guanine) repeat in the 3'-untranslated region of a protein kinase gene contributes to the development of myotonic dystrophy. We have diagnosed and experienced a case of congenital myotonic dystrophy in a neonate with the chief complaint of respiratory difficulty and apnea. So we report the case and the brief review of related literatures.