Abstract: Landrace Yorkshire male pigs were weaned at 7-day old and fed with milk prepared by milk-replacing powder (MRP) and water. At 9-day old, twelve pigs were randomly assigned into control (basic diet) or glycyrrhetinic acid (GA) group (MRP containing 200 mg/kg GA) according to body weight, 6 pigs each. The pigs were fed with corresponding feed for 12 days. Pigs were weighed and killed at 21-day old, and the viscera index, the protein content in enterocytes of small intestine and the ornithine decarboxylase (ODC) activity in that of jejunum, and the villus height, crypt and lamina propria depth of jejunum and ileum were determined. The results showed that, compared with the control, the liver index and small intestine mass/length, the villus height of jejunum and ileum and the crypt of ileum in GA group were increased (P<0.05); The ODC activity was enhanced (P<0.01). It is indicated that the development of liver and small intestine of piglet were boosted and the mucosa structure was improved by GA; And increasing ODC activity is one of the potentially molecular mechanism of GA on the small intestine.