Objective：To explore the value of extracellular volume fraction（ECV）measured by dual-energy computed tomography （DECT）in differentiating benign and malignant intraductal papillary mucinous neoplasms（IPMN）. Methods：A total of 57 patients with IPMN confirmed by surgical pathology and underwent DECT examination within one month before the operation were retrospectively collected between June 2018 and December 2021. According to pathological results，the patients were divided into benign group（28 cases）and malignant group（29 cases），and the iodine concentration（IC）of pancreatic parenchyma within 1 cm around the lesions and abdominal aorta on the same picture in the delayed-phase were measured respectively，and the value of DECT- ECV was calculated according to the formula：（IC_pancreas/IC_{abdominal aorta}）×（1-Hematocrit）. The clinical and imaging data of the two groups were analyzed by univariate analysis and multivariate logistic regression analysis to determine the independent risk factors，and the imaging model，clinical model and imaging combined clinical model were constructed respectively. The performance of each model was evaluated according to the area under curve（AUC）under the receiver operating characteristic（ROC）curve，and the diagnostic efficency of each model was compared by Delong test. Results：Multivariate analysis showed that the DECT-ECV，the elevated level of carbohydrate antigen（CA）19-9，and the history of acute pancreatitis（AP）were independent risk factors for differentiating benign andmalignant IPMN. The AUC of imaging model（DECT-ECV），clinical model（the elevated level of CA19-9 and the history of AP），and imaging combined clinical model（DECT-ECV，the elevated level of CA19-9 and the history of AP）in diagnosing malignant IPMN were 0.808，0.759，and 0.884，respectively. The diagnostic efficacy of imaging combined clinical model was significantly higher than that of clinical model. Conclusion：DECT-ECV of the pancreas parenchyma around the lesions may differentiate benign and malignant IPMN， and provide a certain reference for clinical treatment.