In this study, we aimed to investigate the effect of GamiChungYi-tang(GCY-t) on caerulein-induced acute pancreatitis (AP). It is performed by detecting oxidative stress markers and observing histopathological examination. Thirty adult male rats(Sprague-Dawley) were divided into six groups as follows: normal (NOR,n=5), caerulein-induced (CON,n=5), caerulein+Cefotaxime Sodium(CT,n=5), caerulein+GCY-t (130 mg/kg, CHA,n=5), caerulein+GCY-t (260 mg/kg, CHB,n=5) and caerulein+GCY-t (520 mg/kg, CHC,n=5) groups. Pancreatic tissues of rats from all groups were removed for apoptosis and light, and electron microscopic examination. Blood of rats from all groups were collected for oxidative stress markers inspection and pathological examination. Pancreatic oxidative stress markers were evaluated by the measurements of leukocyte, serum amylase and platelet activating factor (PAF), Interleukin-6 (IL-6) levels were determined spectrophotometrically. CON group has a significant increase (p<0.05) in amylase compared with NOR, but CT and CHA, CHB, CHC groups reduced the levels of these enzyme. The levels of Platelet activating factor (PAF) were increased in CON compared with NOR, but decreased in CT and CHA, CHB, CHC groups compared with CON. Interleukin-6 (IL-6) levels were increased significantly in CON compared with NOR, but reduced in CT and CHA, CHB, CHC groups. In the observations of Optical microscopy and electron microscopy, The experimental groups showed the significant decreases in pancreatic tissue inflammation, edema, vacuolization, necrosis compared to the control group. After all, GCY-t is potentially capable of limiting pancreatic damage produced during AP by restoring the fine structure of acinar cells and tissue.