Abstract：Recurrent oral ulcer(ROU) is a common oral mucosal disease，which is difficult to be cured after delayed treatment and is often recurrent. The pathogenesis of ROU is complex，and there is a lack of targeted therapeutic agents. The authors apply Chinese medicine sequential therapy to treat ROU， and achieve a good curative effect， which can shorten the course of disease and reduce the recurrence. Its pathogenesis is closely related to the heart， spleen and kidney. The main syndromes include heat accumulation in the heart and spleen，spleen-stomach qi deficiency，and yin deficiency resulting in vigorous fire and so on. The treatment is based on different stages，namely the episode period and the intermittent period. During the episode period of heat accumulation in the heart and spleen syndrome， the basic treatment is to clear heat and purge fire， with modified Xiexin Daochi Powder as the main prescription； during the intermittent period，the main treatment is to nourish yin，assisted with clearing heat，and use Ophiopogonis Radix，Lophatheri Herba and Glycyrrhizaeare Radix et Rhizoma as tea for drinking. During the episode period of spleen-stomach qi deficiency，the treatment method is warming and supplementing the spleen and stomach to control fire，with modified Butu Fuhuo Tang as the main prescription；during the intermittent period，the main treatment is to supplement the spleen，with Xiangsha Liujunzi Pills to rectify qi and fortify the spleen for patients with qi stagnation and Shenling Baizhu Pills to fortify the spleen and drain dampness for patients with dampness obstruction. During the episode period of yin deficiency resulting in vigorous fire， the treatment method is enriching yin and subduing fire， with modified Sancai Fengsiu Pellet as the main prescription；during the intermittent period，the treatment is mainly to enrich and nourish kidney water， with Liuwei Dihuang Pills for recuperative medical care. It is suggested that during the episode period，the patients should be treated with Chinese medicine decoction until the pain disappeared and the ulcer healed； during the intermittent period， the patients are given tea or oral administration of Chinese medicine pills according to their constitution so as to prevent recurrence. It is emphasized that in order to achieve a good clinical effect，it is necessary to examine the syndrome and find out the cause，master the basic laws and know how to respond flexibly to specific situations，and flexibly modify and apply the prescriptions. Chinese medicine sequential therapy for ROU reflects the concept of controlling the development of existing disease and preventing disease before it arises，which can provide a new idea for the clinical treatment of ROU.