Abstract: This experiment was conducted to study the distribution characteristics and patterns of IgA and IgG secreting cells in the different sites of the gastrointestinal tract of the weaning piglets. Tissue samples of gastric fundus, gastric body, gastric pylorus, duodenum, jejunum, ileum and colon were collected from eight piglets weaned for 24 days. These tissue samples were studied by immunohistochemistry methods for detecting the changes of IgA and IgG secreting cells in the gastrointestinal tract. The results showed that the distribution of IgA and IgG secreting cells along the gastrointestinal tract had similar distribution tendency and patterns. IgA and IgG secreting cells were mainly distributed in the lamina propria, and the numbers of the two sorts of secreting cells were firstly increasing and then decreasing along the gastrointestinal tract. In addition, IgA and IgG secreting cells were mostly distributed in the gastric pylorus and the small intestine. These results demonstrated that the gastric pylorus and the anterior segment of the small intestine of piglets may be the important sites of playing the mucosal immune reactions and protecting against the pathogenic microorganism.