Abstract: Low-grade myofibroblastic sarcoma(LGMS) is an extremely rare malignant tumor of myofibroblastic cells that primarily affects the head and neck region. LGMS occurring in the oral cavity is commonly found on the tongue, and those occurring in the jawbone are less common, with only 12 reported cases to date. LGMS is often in adult males but rare in children. This report describes a rare case of LGMS in the mandible of a child who underwent surgical resection. Histopathological examination revealed spindle cell proliferation with invasive growth into surrounding skeletal muscle. Immunohistochemical staining showed positive expression of Vimentin, Calponin, SMA, and Actin, supporting myofibroblastic and smooth muscle differentiation of the tumor and the diagnosis of LGMS. This article, based on this case and relevant literature, discusses the immunological and pathological characteristics, treatment and prognosis of LGMS in the jawbone, in order to enrich clinicians' understanding and improve the diagnosis of this disease.