Objective To study the clinical features, diagnosis, treatments and prognosis of Ewing sarcoma(ES) of the ethmoid sinus in children.Methods The clinical data of one case of ES were analyzed and discussed in combination with relevant literature.Results This patient had primary ethmoid ES. The preoperative diagnosis lacks specific clinical manifestations and imaging features.The final diagnosis was confirmed by histopathology and immunohistochemistry. The patient was treated with surgery combined with chemotherapy and radiotherapy, and no recurrence or metastasis after 8 months of follow-up.Conclusion Ewing sarcoma of the ethmoid sinus is extremely rare, which lacks typical and specific of clinical manifestations.The pathological features are similar to small round cells of other tumors in nasal cavity.Immunomarker CD99+NKX2.2 is recommended for diagnosis of ES. The prognosis of ES of the ethmoid sinus is better with comprehensive treatment.