The technique of  auto  text categorization is the foundation in text mining, and text feature selection is the core of the text categorization. Concept lattice is a very effective method to extract rules and data analysis, however, its building efficiency is very low. This paper extracts the rules of the text categorization based on the extended concept lattices model, takes advantage of concept lattice in the categorization rule extracting which eliminates the useless concepts. This method can extract all rules by using a few concepts, which is efficient. This algorithm shows in the environment of running MATLAB7.0 that the recallprecision is slightly lower than KNN and SVM ,but precision ratio is higher than them. Therefore, if the classification rules are applied to text categorization, the categorization effect can be comparable with KNN and SVM.