Abstract: Objective　To compare the values of serum citrulline, intestinal fatty acid binding protein (IFABP) and intestinal trefoil factor (ITF) in diagnosis of acute gastrointestinal injury in critically ill children. Methods　A total of 84 critically ill children were enrolled. The serum citrullin, IFABP, and ITF were measured by high performance liquid chromatography and enzyme-linked immunosorbent assay. The testing results and clinical data were analyzed. Results　Compared with non gastrointestinal injury group, the serum citrulline level was significantly lower and IFABP and ITF levels were significantly higher in gastrointestinal injury group (all P<0.05). In critically ill children, the serum citrulline level was negatively correlated with C-reactive protein, procalcitonin and hospitalization time (r=-0.36 to -0.31, P<0.01). Conclusions　The levels of citrulline, IFABP and ITF have diagnostic values for acute gastrointestinal injury in critically ill children. The level of citrulline may reflect the degree of acute gastrointestinal injury in critically ill children.