Objective To investigate the mechanism of gastrointestinal motility disorder of severe acute pancreatitis （SAP） in rats. Methods SD rats were randomly divided into 2 groups：sham operation （SO） group （n=16） and SAP group （n=16）. The gastric antrum interdigestive myoelectric complex （IMC） of rat was recorded by using bipolar silver electrode recording， the concentration of serum motilin （MTL） and vasoactive intestinal peptide （VIP） were detected by enzyme-linked immunosorbent assay （ELISA） method， and determined the pancreatic pathology score. Results Compared with SO group， the concentration of serum MTL obvious decreased and the concentration of VIP obvious rised in SAP group （P＜0.01）. Compared with SO group， the time of IMC cycle， andⅠand Ⅱ phase were extended， and time of Ⅲ phase was shortened， also the amplitude and frequency of peak electric of Ⅲ phase were declined in SAP group （P＜0.01）. And the concentration of MTL in SAP group showed positive correlation with the time of Ⅲ phase of IMC （r=0.967， P＜0.01）， the concentration of VIP in SAP group showed negative correlation with the time of Ⅲ phase of IMC （r=-0.592， P＜0.05）. The pancreatic organization pathological score in SAP group was higher than that in SO group （P＜0.01）. Conclusion There is gastrointestinal motility disorder in SAP rats， furthermore， it may induce gastrointestinal motility disorder through effecting the gastrointestinal smooth muscle electrical activity.