Objective To investigate the therapeutic effect of sodium aescinate (SA) on severe acute pancreatitis (SAP) in rats.Methods SAP model was induced by intraductal administration of 5％ taurocholic acid sodium salt.SD rats were then randomly divided into 3 groups (n =16),namely sham,model and SA group (5 mg/kg).Drugs or saline(10 ml/kg) were administered via caudal vein 30 min post-operation.The serum amylase was measured with spectrophotometer and pancreatic histological changes were observed under microscope 6 h and 12 h post-operation,respectiveiy.Results Pancreatic histological grades in the model group were (9.42 ± 1.06) and (18.30± 2.18) 6 h and 12 h post-operation,respectively,which showed significant differences (P＜0.01) compared with the sham group [(0.55 ±0.20) and 0,respectively].SA evidently reduced the severity of pancreatic pathology and improved the tissue inflammation in rats with SAP.Pancreatic histological grades were (7.85±1.33) and (12.75±1.69)in the SA group 6 h and 12 h post-operation,respectively,which had significant differences compared with the model group (P＜0.05).Serum amylase levels in model group were (2612 ± 59) U/L and(3004±687)U/L6 h and 12 h post-operation,respectively,which showed significant differences (P ＜ 0.01) compared with the sham group [(928 ± 271) and (890± 295) U/L,respectively].Serum amylase levels were reduced to (1790± 336) U/L and (2093 ± 298) U/L in the SA group 6 h and 12 h post-operation,respectively.SA markedly inhibited the level of serum amylase compared to the model group (P＜0.01).Conclusion SA could protect rats with SAP effectively.