Mucopolysaccharidosis (MPS) is a group of diseases in which acidic mucopolysaccharide molecules cannot be degraded and accumulate in the lysosomes due to lysosomal enzyme defects. According to the clinical manifestations and enzyme defects, mucopolysaccharidosis can be divided into 8 types, such as I, II, III, IV, IV, VI, VII, and IX (no type V and VIII). Because of the different treatment and prognosis of each type, to further guide clinical treatment and prenatal diagnosis, we carried out common enzymatic typing of patients with clinically suspected mucopolysaccharide storage disorders. From August 2006 to October 2007, a total of 42 children with suspected mucopolysaccharide storage disorders were seen in the pediatric endocrine genetic metabolic disease clinic. The clinical indications of suspected mucopolysaccharide storage disease included growth retardation, ugly face, skeletal deformities, enlarged liver and spleen, mental retardation, and joint stiffness/looseness. Peripheral blood was collected from children with suspected mucopolysaccharide storage disease, and leukocytes were isolated, and the enzymes responsible for MPS I, MPS II, MPS IVA, MPS IVB, MPS VI and MPS VII deficiencies, α-L-adulosidase, aldolase, galactosamine-6-sulfate, β-galactosidase, aryl sulfatase B and β-glucuronidase, respectively, were measured by artificial fluorescent substrate and biochemical methods. -glucuronidase activity. Among the 42 suspected children, 33 cases of mucopolysaccharide storage were diagnosed, including 5 cases of type I (15.2% of the diagnosed cases), 19 cases of type II (57.6%) and 9 cases of type IVA (27.2%), while MPS type IVB, MPS type VI and MPS type VII were not found, and 9 patients were not diagnosed. MPS type II is probably the most predominant type of mucopolysaccharide storage disease in Chinese, while other more common types are IVA and type I. When clinical findings of children with suspected mucopolysaccharide storage are not clearly indicative of enzymatic defects, we propose 2 simple diagnostic ideas: since joint laxity is a characteristic manifestation of IVA, when a child with suspected mucopolysaccharide storage shows joint laxity, the activity of galactosamine-6-sulfate enzyme should be analyzed first; if the child does not show joint laxity and is If the child does not show joint laxity and is male, the analysis can be started with the most common MPS type II, which can lead to a rapid diagnosis of the child.