Objective：This study aims to investigate the diagnostic value of inflammatory markers including neutrophil/lymphocyte（NLR）and platelet/lymphocyte（PLR）in malignant transformation of pancreatic intraductal papillary mucinous neoplasm（IPMN）. Methods：The IPMN patients in the First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2020 were retrospectively analyzed. The general information，clinical indexes，imaging indexes and inflammatory indexes were collected，and the nomogram was used to construct the prognostic model of malignant IPMN. Results：NLR，PLR，CA19-9，（carcino embryonic antigen，CEA），cyst size，enhanced mural nodule and abrupt changes in the pancreatic duct caliber were associated with the malignant progression of IPMN. NLR，CA19-9 and cyst size were independent risk factors for malignant IPMN. PLR and cyst size were independent risk factors for IPMN with high-grade dysplasia（HGD）. CA19-9 was an independent risk factor for IPMN with invasive carcinoma（IPMC）. The area under the curve for predicting malignant IPMN based on NLR，CA19-9 and cyst size was 0.806. The prognostic model had good prediction performance. Conclusion：NLR，CA19-9 and cyst size were independent risk factors for predicting malignant IPMN，while PLR and cyst size were independent risk factors for predicting HGD. Inflammatory markers played important role in the malignant progression of IPMN，which can be used as a useful supplement to Fukuoka guidelines.