Abstract： Objective： To observe the clinical effect of electro- acupuncture at auricular vagus nerve for diarrhea predominant irritable bowel syndrome(IBS-D). Methods：A total of 22 cases of IBS-D patients were randomly divided into 12 cases in the observation group and 10 cases in the control group，of which 2 cases were excluded from the observation group and then 10 cases were finally included. The control group was treated with Changjiling prescription， and the observation group was treated with electro-acupuncture at auricular vagus nerve. Both groups were treated for four weeks. Before and after treatment， the scores of Irritable Bowel Syndrome Symptom Severity Scale(IBS- SSS)， Irritable Bowel Syndrome Quality of Life(IBS- QOL)， Hamilton Depression Scale(HAMD) and Hamilton Anxiety Scale(HAMA) in the two groups were compared. The adverse reactions in the two groups were compared. Results：After treatment，the IBS- SSS scores in the two groups were decreased when compared with those before treatment(P＜0.05)， and there was no significant difference being found in the comparison of IBS-SSS scores between the two groups(P＞0.05). After treatment， the scores of dysthymia，behavior disorder，health concerns and social function and the total scores in the observation group as well as the scores of dysthymia， self- image， health concerns and relationship development in the control group were decreased when compared with those before treatment， differences being significant(P＜0.05)； there was no significant difference being found in the comparison of the above scores of IBS- QOL between the two groups(P＞0.05). After treatment，the HAMD scores in the two groups were decreased when compared with those before treatment(P＜0.05)，and there was no significant difference being found in the comparison of the HAMD scores between the two groups(P＞0.05)； the HAMA scores in the two groups were decreased when compared with those before treatment(P＜0.05)，and the HAMA score in the observation group was lower than that in the control group(P＜0.05). During treatment， there was no serious adverse reaction in the two groups. Conclusion： Electro- acupuncture at auricular vagus nerve for IBS- D can effectively improve symptoms and quality of life， and relieve emotions like anxiety and depression of patients， which is a safe and effective treatment method.