Abstract： Objective： To observe the clinical effect of Tongmi mixture for senile patients with constipation with qi- yin deficiency syndrome and its effect on intestinal flora. Methods：A total of 70 cases of senile patients with constipation with qiyin deficiency syndrome were selected and randomly divided into the treatment group and the control group， 35 cases in each group. The treatment group was given Tongmi mixture，and the control group was given Qirong Runchang oral liquid. Both groups were treated for one month. The clinical effect was compared between the two groups. Before and after treatment，scores of stool characteristics，sweating and panting after defecate，abdominal distension and abdominal pain， and defecation smoothness were compared between the two groups. Before and after treatment，levels of escherichia coli， lactobacillus， and bifidobacterium， as well as the ratio of bifidobacterium to escherichia coli(B/E) were compared between the two groups. Results： The total effective rate was 97.15% in the treatment group， higher than that of 77.14% in the control group(P＜0.05). After treatment，scores of stool characteristics，sweating and panting after defecation，abdominal distension and abdominal pain，and defecation smoothness in the two groups were decreased when compared with those before treatment(P＜0.05)，and the four symptom scores above in the treatment group were lower than those in the control group(P＜0.05). After treatment，levels of escherichia coli，lactobacillus，and bifidobacterium，as well as the B/E value in the two groups were increased when compared with those before treatment(P＜0.05)， and the four indexes above in the treatment group were higher than those in the control group(P＜0.05). Conclusion：In the treatment of senile patients with constipation with qi- yin deficiency syndrome， Tongmi mixture can significantly improve their clinical symptoms， and improve levels of escherichia coli，lactobacillus，and bifidobacterium.