Objective:To analyze the characteristics of otorhinolaryngological clinical manifestations in children with Mucopolysaccharide(MPS) type Ⅰ and type II in order to improve the knowledge of otorhinolaryngologists about this disease. Methods:Clinical data related to 55 children with MPS type Ⅰ and type II were retrospectively analyzed to investigate the clinical manifestations of MPS in ENT. Results:All 40 patients(72.72%) with MPS had at least one ENT symptom during the course of the disease, with 95% of them having an ENT symptom prior to the diagnosis of MPS; upper airway obstruction was the most common ENT symptom(34, 85.00%), followed by recurrent upper respiratory tract infections(23, 57.50%), and lastly, hearing loss(11, 27.50%); all 26 patients had undergone at least one surgical procedure, of which 15(57.69%) had undergone ENT surgery, and all of these patients underwent ENT surgery before diagnosis. The most common ENT surgery was adenoidectomy. Conclusion:Early clinical manifestations of MPS patients are atypical, but the early and prevalent appearance of otolaryngologic symptoms and increased awareness of the disease among otolaryngologists has a positive impact on the prognosis of MPS.