Objective:To investigate the predictive value of atherogenic index of plasma (AIP) in the assessment of acute pancreatitis (AP).Methods:598 patients diagnosed with AP admitted to the Affiliated Hospital of Yangzhou University between January 2016 and December 2020 were recruited and divided into severe acute pancreatitis group (SAP group, n=57) and non-severe acute pancreatitis group (non SAP group, n=541) according to the Atlanta Classification (2012 revision). General clinical data and related biochemical indicators of all enrolled patients were collected, and Bedside Index of Acute Pancreatitis Severity (BISAP) score, Ranson score and CT Severity Index (CTSI) score were performed. The risk factors of SAP were analyzed by logistic regression. Receiver operating characteristic (ROC) curve was used to analyze the evaluation value of AIP and various scoring systems on the severity of pancreatitis. Results:The AIP, white blood cell (WBC), neutrophil count (NEUT), fasting blood glucose (FBG), serum total cholesterol (TC) level, proportion of hyperlipidemia, proportion of diabetes, Ranson score, BISAP score, CTSI score of patients in SAP group were higher than those in non SAP group, and the difference was statistically significant (all P<0.05). Multivariate logistic regression analysis showed that AIP was an independent risk factor for SAP ( P<0.05). ROC curve showed that the are under the curve (AUC) of SAP predicted by AIP was 0.706(95% CI: 0.631-0.782, P<0.001). Conclusions:AIP is an independent risk factor for SAP, which helps to assess the severity of AP.