Abstract: AIM To analyze the relationship between clinical characteristics and plasma D-dimer (DD) level in patients with acute pancreatitis (AP) diagnosed over the past 2 years at the 101 Hospital of PLA.METHODS From 2014 to 2016,152 patients diagnosed with AP were divided into three groups according to the severity of illness:a mild acute pancreatitis (MAP) group (111 cases),a moderately severe acute pancreatitis (MSAP) group (52 cases),and a severe acute pancreatitis (SAP) group (9 cases).The correlation of plasma level of D-dimer with Ranson and CTSI scores,length of stay,and hospitalization cost was analyzed.RESULTS Plasma level of D-dimer was significantly higher in the MSAP and SAP groups than in the MAP group (P < 0.01),but there was no significant difference between the MSAP and SAP groups.In addition,hospitalization days and cost differed significantly among the three groups (P < 0.01).Plasma level of D-dimer was positively correlated with length of stay,hospitalization cost,Ranson score,and CTSI score (r =0.429,0.436,0.402,0.447).CONCLUSION Plasma level of D-dimer increases with the increase in the severity of AP,and it positively correlates with hospitalization time,cost,Ranson score,and CTSI score.Plasma level of D-dimer may be used for early evaluation of the severity of AP.