【Objective】To reveal the molecular genetic mechanism of 7 cases that suspected Maroteaux_Lamy syndrome（MPSⅥ），we analyze the ARSB gene of proband and their parents and identify the pathogenicity of novel mutation，which lay foundation for prenatal diagnosis or preimplantation genetic diagnosis（PGD）in the future. 【Methods】On the basis of clinical preliminary diagnosis，GAG urinetest and the detection of MPS enzyme activity，and the EDTA anti-coagulated blood was collected from proband and their parents then perform PCR amplification and Sanger sequencing of the ARSB gene. After the novel mutations were detected and verified by databases such as HGMD，1000G and ExAC. At first，spatial conformation of mutant protein and normal protein were analyzed and compared by SWISS MODEL.Then conservation analysis of cross-species amino acids by Clustal X. What’s more，pathogenicity prediction methods including PROVEAN，SIFT and PolyPhen-2 were applied. Finally，the pathogenicity of the novel mutation was comprehensively analyzed and identified by ACMG standard.【Results】 1）The genetictest results of the 7 family proband were as follows. Family 1，c.574T>C/p.C192R homozygousmissense mutation.Family2，c.160G>A/p.D54N（from mother）and c.1197C>G/p.F399L（from father）compound heterozygote. Family3，except for c.1072G>A/p.V358Mand IVS5as（-27）A>C，no other mutations were found in the rest exons but the enzymatic and clinical phenotypes were in accordance with MPStypeVI. Family4，c.281C>T/p.S94L（novel mutation，from mother）and IVS5 as（-27）A>C （from father）compound heterozygote. Family 5，c.1197 C > G/. F399L homozygous missense mutation. Family 6， c.1197C > G/p.F399L（from mother）and c.1379C > T/p.S460F（novel mutation，from father）compound heterozygote. Family 7，c.499G>A/p.G167R（from father）and c.1325C>T，p.T442M（from mother）compound heterozygote. 2） Identification results of novel mutation. The spatial conformation predictions for normal ARSB enzyme protein and p.S94L mutant enzyme protein show that the reisaclear difference between them，cross-species conservation analysis results show that the amino acid at the mutation point has a high degree of evolution in the species conservatism. PROVEAN， SIFT and PolyPhen-2 predictions results are Deleterious，Damaging and Probably damaging. The predicted results of above methods for p.S460F and the analysis results of ACMG also indicate that the mutation may be pathogenic. 【Conclusion】1）The new mutation in p.S94L in family 4 and p.S460F in family6 maybe novel pathogenic mutations， which may be one of the intrinsic causes of children with disease. 2）Family1， 2， 5， 6， 7 can be diagnosed as MPS type VI，and its genotype and phenotype have significant correlation. Although family 3 was diagnosed as MPS type VI by enzymatic examination，clinical symptoms and urine test results. We failed to find clear mutations at DNA level in ARSB gene，so the correlation between its phenotypeand genotype remains to be further confirmed.