Abstract: OBJECTIVE To investigate whether Tong-Xie-Yao-Fang (TXYF) could play a therapeutic role in IBS-D by regulating intestinal flora. METHODS In this paper， twenty-four Sprague Dawley (SD) rats were randomly divided into four groups: control， IBS-D model， TXYF and pinaverium bromide positive groups. IBS-D model was established by given senna decoction intragastrically and chronic restraint stress. Then， these IBS-D model rats were treated with TXYF. Traditional pharmacology indexes， including body weight variety， pathological examination and abdominal withdrawal reflex (AWR) scores were tested. The number of rats that suffered with diarrhea were also counted. Furthermore， fecal microbiota alterations were assayed by 16S rRNA high-throughput sequencing. RESULTS Pharmacology indexes and diarrhea rate of model group indicated that IBS-D model was established successfully. According to the results， diarrhea of IBS-D rats could be controlled by TXYF treatment. Body weight and AWR scores (P<0.001) of TXYF group were found significantly higher than model group. Compared with model group， the results of fecal microbiota showed that the community richness and diversity for TXYF group were improved. Fecal microbiota analyzed in phylum displayed that the abundance of Bacteroidetes was increased， while those of Proteobacteria， Spiroch-aetae and Verrucomicrobia were decreased. CONCLUSION TXYF is proved to be beneficial to IBS-D rats through modifying the abundance of gut microbiota.