Objective:To observe the clinical efficacy of “Yimu Futu Formula” for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D) of liver qi subjugating spleen pattern  Methods:Sixty cases with IBS-D were randomized into treatment group and control group, with 30 cases in each group. The treatment group was treated with “Yimu Futu Formula”, and control group was treated with pinaverium bromide, with the course of 4 weeks. The clinical efficacy, IBS symptom score and life quality score were observed  Results:The total effective rate was 93.3% in the treatment group and 73.3% in the control group, with a difference between the two groups (P<0.05). After treatment, the IBS symptom score in both groups were decreased (P<0.01), and the reduction of symptom score in the treatment group was much more than that of the controls (P<0.05, P<0.01). After treatment, the life quality score in both groups were decreased (P<0.01), and increase of the treatment group was much more than that of the controls (P<0.01)  Conclusion: “Yimu Futu Formula” is effective to improve the clinical symptoms in patients with IBS-D and improve their quality of life.