Objective To study the relationship between the oncosis of pancreatic acinar cells and activa-tion of macrophage in rat model of acute pancreatitis (AP). Methods The pancreatic acinar cells were isolated by two-step enzyme digestion, and then they were divided into control group, AP group and test group. Pancreatic acinar cells were cultured with caerulein in AP group, with caerulein and endothelin in test group, and with culture medium in control group. The oncesis rate of the pancreatic acinar cells was detected after acridine orange and ethidium bromide fluorescent staining. The supernatant was collected to detect the release of amylase and lactate dehydrogenase (LDH). The macrophages were cultured with 1 ml of supematant for 6 hours, and then the protein level of tumor necrosis factor-α (TNF-α) was measured by ELISA. Results Few oncotic pancreatic acinar cells were observed in the control group, and the levels of amylase and LDH secreted by pancreatic acinar cells and TNF-α secreted by macrophage were (1175±165)kU/L, (846±118)U/L and (36±5)μg/L, respectively. Oncotic pancreatic acinar cells were observed in AP group, and the levels of amylase, LDH and TNF-α were (7130±680) kU/L, (4262±626) U/L and (155±18) μg/L, respectively, which were significantly higher than those in control group (t = 5.184, 4.277, 3.665, P < 0.05). The levels of amylase, LDH and TNF-α were even higher in test group, and they were (9240±1177) kU/L, (6937±893)U/L and (268±35)μg/L, respectively, which were significantly higher than those in AP group (t = 2.251, 2.825, 2.843, P < 0.05). Conclusions The release of amylase was changed as the oncosis of pancreatic acinar cells occurred. The secretion of TNF-α was along with the degree of oncosis of pancreatic acinar cells. The results of the study indicate that a relationship exists among the inflammatory response of macrophage, the release of contents of pancreatic acinar cells and the oncosis of the pancreatic acinar cells.