Objective To discuss the application of three attribute reduction methods in data reduction of syndrome in TCM.Methods Bivariate correlation analysis

principal component analysis and rough set were respectively performed for attribute reduction on the same TCM syndrome data set of primary insomnia.A C 4.5 decision tree classification models of pathogenic fire derived from stagnation of liver-QI of primary insomnia was established

evaluated by 5-fold cross-validation.Results Every index of rough set reduction model was better than the other reduction models.Its area under the ROC curve was larger than the other two models with statistic significance（P<0.05）.There was no significant different between correlation reduction model and principal component reduction model（P>0.05）.Conclusions The model built by attribute reduction method based on rough set could maintain a high capability of classification.The reduction could eliminate unnecessary knowledge from the information system（Decision Tables） as far as possible

result in a small subset with well ability of classification.And it is a feasible reduction method in TCM syndrome data processing.