AIM:To observe the protective effect of combined i.v. administraction of Yuanhu injection (YHI) and Huoxuehuayu injection-I (HHI-I) against acute pancreatitis (AP) in rabbits.METHODS:Sever acute pancreatitis (SAP) was induced by retrograde infusion of artificial bile juice into biliary-pancreatic duct, and treated with YHI and HHI-I intravenously. The protective effect was judged by the survival time and rate, serum amylase, serum interleukin-6, pancreatic microcirculation and pathological alteration.RESULTS:Combined use of YHI and HHI-I could markedly increase the rabbits' 5-day survival rate after AP (83.3% in the treatment group and 33.3% in control). The serum amylase value (x-± s) decreased to 1596.6U/L± 760.50U/L in the 5th day from the high level (6320.83U/L± 2614.12U/L) in the 1st day after AP in the treatment group, while in the control group the amylase activity in the 5th day was 2095.0U/L± 1081.87U/L, being significantly different from that before AP (837.17U/L± 189.12U/L). YHI and HHI-I also obviously improved the pancreatic microcirculation and lowered the serum interleukin-6 level, one of the indices of severe pancreatitis. Pathological examination indicated all the changes typical for AP in YHI and HHI-I treatment group were milder than those in the control.CONCLUSION:YHI and HHI-I used in combination might have protective effect against acute pancreatitis in rabbits.