The authors have observed a case of eosinophilic granuloma which occurred in 10 years old girl 1.The lesion which occurred swelling and facial disfigurement , was located in the right side of ramus mandible, but toothache and loosening of tooth was absent. 2. Roentgenograph showed bean-sized monocystic radiolucent shadow in mandible border.3. Microscopically,few hemorrhagic araas were existed, and numerous eosinophilic leukocytes eosinophilic myelocyteswith inflammatory cells were infiltrated.