To explore the clinical efficacy of Total Glucosides of White Paeony Capsules combined with iodine glycerol in recurrent oral ulcer(ROU)and its effects on immune function.Methods：A total of 112 patients with ROU admitted in the Fangshan District Hospital of Traditional Chinese Medicine from January 2015 to July 2018 were selected as research objects,and they were randomly divided into observation group and control group,with 56 cases in each group.The control group was treated with common therapy for ROU,and the observation group was treated with Total Glucosides of White Paeony Capsules combined with iodine glycerol.The clinical efficacy,levels of inflammatory factors,immunoglobulin,and T lymphocytes and clinical observational indexes were compared between the 2 groups.Results：The total effective rate of the observation group was significantly higher than that of the control group(P<0.05).After the treatment,the onset time of pain relief,the duration of ulcer and the score of visual analogue scale(VAS)in the observation group were significantly lower than those in the control group(P<0.05).After the treatment,the levels of CD3+,CD4+,CD8+ and CD4+/CD8+ were increased in both groups,and the levels of CD3+,CD4+,CD8+ and CD4+/CD8+ in the observation group were higher than those in the control group(P<0.05).After the treatment,the levels of interleukin-1(IL-1),interleukin-6(IL-6)and tumor necrosis factor-(TNF-)were decreased in both groups,and the levels of IL-1,IL-6 and TNF-α in the observation group were significantly lower than those in the control group(P<0.05).Before and after the treatment,there were no significant differences in the levels of immunoglobulin A(IgA),immunoglobulin G(IgG)and immunoglobulin M(IgM)between the 2 groups(P>0.05).Conclusion：Total Glucosides of White Paeony Capsules combined with iodine glycerol in the treatment of ROU has good efficacy.It can effectively improve immune function of the body,suppress inflammatory reaction,improve patients' clinical symptoms and reduce pain,which is worthy for clinical application.