Children anorexia has been one of the common clinical diseases in recent years. Its etiology, physiological and pathological changes have become the focus of research. The reducing of gastrointestinal motility is one of important reasons. According to the theory "For invigorating spleen, it抯 better to activate it than to tonify it" which was put forward by professor Jiang yuren, we have done some experiments and probed the mechenism of Yunpi method on improving gastrointestinal motility and repairing gastrointestinal absorbent cells' ultrastructure of the anorexia animal model.Based on the clinical research of treating children anorexia by Yunpi method, we imitated the main etiology and symptom in making an animal model, and determined the changes of its gastrointestinal hormone such as gastrin , substance P, vasoactive intestinal polypeptide, somatostatin, nitrous oxide, 5-hydroxytryptamine of the antral, duodenum and the colon. We wanted to reveal the correlation between the abnormality of the gastrointestinal hormone and that of the gastrointestinal motility. We observed the pathological changes of the ultrastructure in antral mucosa epithelial cells, basostomach adenoparietal cells and chief cells, the pathological changes of the intestinal mucosa epithelial cells?microvillus, the endoplast and the connection of the cells by transmission electron microscope. We verified that the changes of the gastrointestinal absorbent cells were the pathological results of anorexia.Our study suggests that the mechanism of Yunpi method onNanjing University of TCMNanjing Wan lisheng May 2001 - 2 -children anorexia relies on four aspects. Firstly, the method can regulate the disorder of gastrointestinal hermone of the anorexia animal model. Secondly, it can stimulate its gastrointestinal motility. Thirdly, it can promote the absorbent function of small intestine. Lastly,it can repair the gastrointestinal absorbent cells' ultrastructure of the animal model.