To demonstrate the correlation between intestinal flora and different TCM constitutions by the chi-square test and the construction of a model of the relationship between intestinal flora and different TCM constitutions.Methods:Based on the questionnaire survey，114 subjects were classified by constitutions，the stool was collected from each subject to obtain qualitative data on the relative abundance of intestinal flora at the species level using 16S rRNA sequencing technology，and the intestinal differential flora that were closely related to different TCM constitutions were screened by chi-square test.Characteristic strains were screened based on the Gini coefficient and the relationship model between intestinal flora and TCM constitutions was constructed using five algorithms，namely NB，IBK，SVM，RF and BPNN，respectively.Results:At the level of chi-square test(P<0.05)，there were significant differences in the relationship between different intestinal strains and nine constitutions to some extent.The relationship model between the two was constructed based on the Gini coefficient; the relationship model could be constructed for all constitutions except for the Qi deficiency type，whose area under the curve of the receiver operating characteristic was above 0.7.Conclusion:The model constructed based on intestinal flora and different TCM constitutions is reasonable and reliable，indicating that different intestinal flora have some correlation with nine TCM constitutions.