Abstract: Pediatric oncology is one of the important cause of children death. PET-CT, which can provide functional and anatomical images in the same scanning session, has a high sensitivity and specialty in the diagnosis of tumors. During the examination of children, careful preparation and individualized dosage are the keys to make it. PET-CT has a great value in making the personal therapy strategy during the clinical activity, including staging, grading, evaluation of therapy, and the items of prognosis and follow-up.