Intraductal papillary mucinous neoplasms (IPMNs) are a rare type of pancreatic cystic tumor, with risk of transforming to pancreatic ductal adenocarcinoma and once it occurs may confer a poor prognosis. Currently, studies on IPMNs are still scarce at home and abroad. Therefore, better understanding the molecular pathological mechanism responsible for IPMNs may have great importance in diagnosis and treatment as well as improving the prognosis of IPMNs. A great amount of oncogenes, tumor suppressor and signaling molecules have been found involving the process of occurrence and development of IPMNs as well as the malignant transformation. In this paper, the authors mainly address the research progress on molecular pathology of IPMNs.