Objective:To Observe the effection of wenpishichang formula on T-lymphocytes subgroup(CD4,CD8,CD4/CD8)and Structure of intestinal mucosa in mice with splcen-yang deficiency diarrhea. Methods: Healthy adult ICR mice . male and female in half. were randomly divided into four groups(normal control group,model control group,fuzilizhong Pill group,high dose group,middle dose group and low dose group), 10 rats in each group. The spleen-yang deficiency diarrhea model of mice were induced by dahuang decoction.One hour after the last treatment,eye blood samples were collected in each groups.The T-lymphocytes subgroup were detected by FCM and the Structure of intestinal mucosa were detected by Light microscope.Results: The levels of CD4 and CD4/CD8 in mice with spleen-yang deficiency diarrhea were lower than the normol control group.The large doses of wenpishichang formula can raise the level of CD4 and CD4/CD8 .The Structure of intestinal mucosa did not have significant changes. Conclusion: Wenpishichang formula can correct the level of T-lymphocytes subgroup in mice with spleen-yang deficiency diarrhea.