Abstract: Objective: To explore the clinicopathological features,immunophenotypes,pathological diagnosis and differential diagnosis of primary pulmonary myxoid sarcoma(PPMS).Methods: The clinical features,histopathological structure and immunophenotypes of a patient treated with right lower lobectomy were analyzed,and the related literature was reviewed.Results: The tumor showed multinodular architecture under microscope,the tumor cells arranged as reticular and cords,and rich myxoid stroma could be found in matrix.Immunohistochemically,the diffusely strong positive vimentin,and locally positive S-100 and epithelial membrane antigen could be used to diagnose the PPMS.Conclusions: PPMS is a very rare lung malignant soft tissue tumor,and its diagnosis mainly depends on the location and histopathologic features of tumor cells,and the detection of Ewing sarcoma breakpoint region 1 gene rearrangement can help to diagnosis.