Objective:To explore the application of decision tree based on entropy in traditional Chinese medicine (TCM) symptom analysis chronic gastritis. Methods: Bootstrap methods were used to multiply 406 cases for data mining, and models for TCM symptom were built using decision tree of C4.5.Results: Twenty-six important factors were selected and ranked according to the importance; readable diagnostic rules were produced and a model was built, of which the correctly classified rate of training set, validation s...