Abstract: Objective To study the relation between gastrointestinal function and severity of acute pancreatitis. Methods Clinical data about 42 patients with acute pancreatitis admitted to our department from September 2001 to August 2012 were retrospectively analyzed. Their gastrointestinal function and acute physiology and chronic health were scored according to the acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ), computer tomography severity index (CTSI) on the day they were admitted. Correlation of the days of moderate-severe gastrointestinal malfunction with the hospital stay days in ICU and the days of mechanical ventilation was analyzed. The proportion of severe patients with moderate-severe gastrointestinal malfunction and those with mild gastrointestinal malfunction was compared. Results The higher the gastrointestinal malfunction score was, the higher the APACHEⅡ score and CTSI score were in patients with acute pancreatitis (r=0.612, P=0.028; r=0.477, P=0.006). The hospital stay days and mechanical ventilation days were positively related with the days of moderate-severe gastrointestinal malfunction (r=0.640, P=0.035; r= 0.779, P=0.022). The proportion of severe patients with moderate-severe gastrointestinal malfunction was higher than that of those with mild gastrointestinal malfunction (χ²=4.367, P=0.037). Conclusion Gastrointestinal function can predict the severity of acute pancreatitis.