Objective To investigate changes in number of endothelial progenitor cells(EPCs)from bone marrow and circulation in mice with acute pancreatitis.Methods BALB/c mice were assigned randomly to saline group and cerulein group.Animals were sacrificed at 12, 24 and 48 hours after injection.Bone marrow and circulating EPCs were detected by flow cyzometric analysis.Plasma VEGF, TNF-α and ET-1 were determined by enzyme-linked immunosorbent assay.The expression of VEGF in the pancreas was assessed by Western blotting.Apoptosis in situ was detected by TUNEL.Results The amounts of EPCs in bone marrow and circulation increased remarkably after cerulein injection(P < 0.05), also the levels of plasma VEGF TNF-α and ET-1(P < 0.05), the EPCs levels in bone marrow and circulation seen in the study closely mirrors the levels of VEGF detected in the circulation(r = 0.77, 0.67 individually).VEGF expression in pancreas was up-regulated after 12 h of cerulein injection compared with that of control group.Apoptosis of endothelial cells also increased in the cerulein group.Conclusion EPCs were mobilized by acute pancreatitis, which may be due to the mobilizing effect of increased levels of VEGF, EPCs may participate in the repair process of injured endothelium induced by acute pancreatitis.