Abstract: The patient,female,27 years old.The scalp neoplasm had been found at her right temple 10 years ago.At first,the size of the tumor was just like a soybean,and did not grow obviously in the past nine and a half years.But the tumor increased fast in these six months,almost as large as the pigeon egg now.The physical examination showed that:A spherical tumor locates in the right temple near the right ear;the size of the tumor is 3cm×4cm×3cm;the surface is smooth,no tenderness,no obvious mobile base,skull defect not touched.Primary diagnosis:the scalp cyst or lipoma.Under the local anesthesia we remove the neoplasm,during the operation we found the lesion located in the subcutaneous tissue layer,involved the galea aponeurosis layer,the skull surface are smooth and complete.The tumor was completely removed.We cut the mass and found a cystic cavity sized 3cm×4cm,which contained gray jerry-built materials,contained oil and a mass of hair,the capsule wall was complete.Postoperative pathological report:The tumor is cystic look throught the microscope,the capsule wall is squamous epithelium,containing keratinized material and hair.The pathological diagnosis is teratoma.The incision healed primarily,no recurrence found for about a year.