Abstract： Objective： To observe the clinical effect of Dachengqi Decoction for chronic functional constipation (CFC) with yangming and bowel excess syndrome. Methods： A total of 150 cases of CFC patients were selected and divided into the observation group and the control group according to the random number table method，with 75 cases in each group. The control group was treated with Mosapride Citrate Dispersible Tablets，and the observation group was additionally treated with Dachengqi Decoction based on the treatment of the control group. After four weeks of treatment，the changes in symptom scores，levels of serological indexes [substance P (SP)， motilin (MTL)， nitric oxide (NO)]， and Patient Assessment of Constipation Quality of Life (PAC-QOL) scores before and after treatment as well as the clinical effects and the incidence of adverse reactions were compared between the two groups. Results： The total effective rate was 96.00% in the observation group and 85.33% in the control group，the difference being significant (P＜0.05). After treatment， the scores of interval time of defecation， each defecation time， stool trait， symptoms such as abdominal distension，difficulty in defecation，and incomplete defecation，and the total scores in the observation group were all decreased when compared with those before treatment (P＜0.05)， and the above scores in the observation group were lower than those in the control group (P＜0.05). After treatment， the levels of SP and MTL in serum in the two groups were increased when compared with those before treatment (P＜0.05)， and NO levels were decreased when compared with those before treatment (P＜0.05)； the levels of SP and MTL in the observation group were higher than those in the control group (P＜0.05)， and the NO level was lower than that in the control group (P＜0.05). After treatment， the scores of physiological， psychosocial， worry， and satisfaction of PAC- QOL scale， and the total scores in the two groups were decreased when compared with those before treatment (P＜0.05)， and the above scores in the observation group were lower than those in the control group (P＜0.05). The incidence of adverse reactions was 6.67% in the observation group and 20.00% in the control group，the difference being significant (P＜0.05). Conclusion：Dachengqi Decoction has an ideal curative effect in the treatment of CFC with yangming and bowel excess syndrome， which can effectively relieve constipation symptoms，improve the levels of gastrointestinal hormone，and enhance intestinal motility and the quality of life，with high safety.