Objective To investigate the value of P-selectin,thrombomodulin (TM) and von Willebrand factor (vWF) in identifying severe acute pancreatitis (SAP) at an early stage of the disease.Methods 80 patients with acute pancreatitis (25 mild,30 moderate and 25 severe) were selected in this study when they were admitted within 24 hours of the onset of symptoms.20 healthy volunteers were collected as the healthy control.Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of vascular endothelial cell damage markers (P-selectin,TM and vWF) in SAP patients and the control group.Results The levels of 3 markers were significantly higher in SAP patients than in the mild and moderate acute pancreatitis patients and healthy volunteers (P＜0.05).P-selectin,TM and vWF were independent markers for the development of SAP and had higher discriminative powers than conventional marker tumor necrosis factor(TNF-α)(P＜0.05).They were similar to the APACHE-Ⅱ scoring system in distinguishing SAP at an early stage.Conclusions P-selectin,TM and vWF are independent markers to identify the development of SAP at an early stage.They are obviously superior to TNF-α and similar to the APACHE-Ⅱ scoring system.