Objective To investigate the clinical features of patients with recurrent acute pancreatitis(RAP)complicated with metabolic syndrome(MS)and the influencing factors of severe disease.Methods The clini-cal data of 382 RAP patients admitted to the hospital from June 2012 to June 2022 were retrospectively analyzed,and they were divided into the MS group(n=142)and the non-MS group(n=240)according to whether they were combined with MS,and into the severe group(n=29)and the non-severe group(n=353)according to the severity.The general data,serological parameters[triglyceride(TG),total cholesterol(TC),white blood cell count(WBC),neutrophil to lymphocyte ratio(NLR),blood calcium,D-dimer(D-D),lactate dehydrogen-ase(LDH),ALT,AST]and ICU occupancy rate and total length of stay were compared among all groups.Bi-nary logistic regression was used to analyze the independent influencing factors of RAP development into se-vere disease,and receiver operating characteristic(ROC)curve was used to analyze the predictive value of each indicator for RAP development.Results Hyperlipidemia was the most common cause of RAP in MS group(66.2％),and biliary origin was the most common cause of RAP in non-MS group(44.6％).There was sig-nificant difference among different causes was statistically significant(P＜0.05).There were significant differences in age,gender,proportion of hypertension,diabetes,MS,length of stay,LDH,blood calcium,D-D and NLR levels between the critical and non-critical groups(P＜0.05).The area under the curve(AUC)of blood calcium,D-D,LDH,NLR and combined diagnosis were 0.759,0.777,0.710,0.621,and 0.841,respec-tively.The AUC of single diagnosis had a certain predictive value,but combined diagnosis had a higher predic-tive value.Conclusion The most common cause in the MS group was hyperlipidemia,and the most common cause in the non-MS group was biliary.Blood calcium.D-D,LDH,NLR are reliable indicators to predict the development of RAP into severe disease,and the accuracy of combined diagnosis is higher.