【Objective】 Identification of gene mutation types in the child with MPS VI，studying the correlation between clinical phenotype and genotype. 【Methods】 Collect clinical data. The second-generation sequencing technology was used to perform MPS VI-related gene sequencing and family verification to identify molecular genetic diagnosis.【 Results】 The main clinical manifestations of children include short stature, dysplasia of skeletal system, stiffness of joint, abnormal development of heart, hearing impairment, special face, exophthalmos and gland hypertrophy, language development, mental retardation. Gene sequencing revealed two heterozygous mutations in the ARSB gene: a known nonsense mutation c.979C > T (p.R327X). The prediction of the three-dimensional structure of the protein suggests that the mutation may lead to the incomplete structure of the protein. A newly discovered whole code mutation c.724_725insCCCTTCAGGTCC (p.H242delinsPLQVH). The local map of the three-dimensional structure of the protein indicates that the amino acid side chain at this site has changed. Family verification showed that the two heterozygous mutations were maternal and paternal, and were autosomal recessive respectively. 【Conclusion】 The newly discovered ARSB compound heterozygous mutation is a pathogenic variation. The correlation between clinical phenotype and genotype is not clear, but it provides reference for clinical diagnosis and treatment, expanding the mutation spectrum of MPS VI gene.