Abstract： Objective To investigate the X-ray,CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs).Methods 14 patients were pathologically diagnosed with pPNETs.The imaging of X-ray (twelve image),Computed Tomography(eleven image) and Magnetic Resonance Imaging(five image) were retrospectively analyzed.Results Of 14 patients,there were two sites of tumour:soft tissue( eight patients) and bones( six patients).For tumoura of the soft tissue region,the appearance of X-ray and CT imaging showed equal or lower density soft mass without dear boundary.In some cases,tumours invaded adjacent bones.The appearance of MRI imaging showed large heterogeneous masses inside soft tissue without clear boundary.Tumours displaced adjacent cortical bone and cavitas medullaris.All masses were heterogeneous enhancement on contrast images.For tumours of bone region,X-ray and CT scan showed large scale osteolysis osteoclasia in bone surrounding with soft tissue masses of various size.The lesions were equal or lower signal on T1 WI.All masses were intermediate or hyperintense signal with heterogeneous midrange or obvious enhancement on T2WI.Conclusion Imaging characteristics of pPNETs were described.X-ray,CT and MRI were useful in understanding the property,extent and staging of tumor and very useful in the diagnosis.