To observe the clinical curative effects of modified Sijunzi Decoction on pediatric constipation of spleen qi deficiency type, and to analyze the effects on parts of hematology indexes and intestinal sensitivity. Methods:A total of 70 cases of children with functional constipation of qi deficiency type who were admitted and treated in Shaanxi Provincial Hospital of TCM from January 2015 to January 2016, who were randomly divided into the control group and the observation group with 35 cases in each group. Patients in control group were adapted to regulate the dietary pattern, strengthen exercise, take Mami'ai (bacillus subtilis and enterococcus faecium with multivitamins granules) with warm water daily. The observation group combined with modified Sijunzi Decoction on the basis treatment of the control group, 1 dose/day, warm-taken in the morning and evening. Both of the two groups of patients were treated for two courses (1 week for a course of treatment). TCM syndrome integrals, the anorectal pressure, oculocardiac reflex test, recumbent-upright test and colonic mucosa Aquaporin 8 (AQP8) of patients of both groups were compared before and after treatment. Results:TCM syndrome integrals of the two groups reduced than before the treatment (P<0.05). The reduction of the observation group was more significantly than that of the control group (P<0.05). The oculocardiac reflex test, recumbent-upright test positive rate of the two groups declined after treatment (P<0.05), and the downward trend of the observation group was more significant, compared with the control group with statistically significant differences (P<0.05). The anorectal pressure of the two groups were improved after treatment, and the observation group improved more significantly. The differences were with statistically significant compared with control group (P<0.05). AQP8 levels of the two groups of the children decreased after treatment and patients in the observation group were lower compared with those in the control group after treatment (P<0.05). Conclusion:The modified Sijunzi Decoction can effectively cure pediatric constipation of spleen qi deficiency type and the mechanism may related to the reduction of AQP8 expression.