Objective To explore the clinical phenotype and genotype characteristics of Cornelia de Lange syndrome (CdLS). Methods The clinical data of Cornelia de Lange syndrome (CdLS) in a child were retrospectively analyzed, and the reported cases in domestic were summarized and analyzed. Results The 1 -year- 2 -month-old female child had special appearance, mental and motor retardation, limb deformity and hearing abnormality. A new heterozygous nonsense mutation of c. 675C>A (p.Y 225 X) was found in the HDAC 8 gene. According to ACMG guidelines, the mutation was predicted to be pathogenic, and CdLS was confirmed. The databases of Wanfang, Weipu, CNKI, and PubMed were searched, and 46 cases of CdLS were reported in China. Among the 26 children who underwent genetic examination, 20 ( 76 . 9 %) had NIPBL gene mutation, 3 ( 11 . 5 %) had HDAC8 gene mutation and 1 ( 3 . 8 %) had SCM1A gene mutation. Two patients had no pathogenic gene variations that were consistent with their clinical manifestations, and the phenotypes were different. Conclusion Children with CdLS have special appearance, growth retardation, multiple organ involvement, and hearing impairment. Most of them can be diagnosed by typical clinical phenotypes. Gene testing can help early diagnosis of atypical patients.