Abstract: Positron emitter tomography (PET) is the unique medical image technique to complete the biologic manifestation and evaluate quantitatively the biochemical change in molecular level of hu-man body in vivo at present, in which 2-deoxy-2- ¹⁸Ffluoro-D-glucose ( ¹⁸F- FDG) PET has been wide-ly used in clinical oncology. Up to now, most clinical researches indicate that ¹⁸F-FDG PET has the following main roles in pancreatic cancer: a) to have the higher diagnosis and differential diagnosis effi-ciency, the sensitivity, specificity and accuracy is 71%-100% 、64%-100% and 85%-93% respectively;b) to detect more lymph node and distant metastases than CT, B-US and MRI, and help to enhance ac-curate clinical staging and choose reasonable treatment program; c) to evaluate the response of tumorsto the radiotherapy and chemiotherapy and detect the recurrence and metastasis after operation in theearly period, thus to provide an objective and accurate basis for the clinic adjusting therapy project and adopting treatment measure in time and D) to availably judge the prognosis of patients with pancreatic cancer through measureing the standardized uptake value (SUV) of ¹⁸F-FDG in tumors.