Abstract: The intelligent system of geotechnical engineering is an important research interest in geotechnical engineering field.A data mining system of loess mechanics was developed based on advanced data mining system in information technology.The data mining system of loess mechanics included the preprocessing module,mining operation module,knowledge base management module,and software interface of geotechnical application.The system could be applied to data reduction,cluster,classification,and prediction for loess mechanics.Through a lot of engineering applications,the results indicated that the system was effect and practical for loess collapse.Through the assessment of each rule in decision trees model by using 2766 groups of loess testing data in 59 projects,the results show that the precision discriminating self weight collapse loess is about 87.3%,and the precision discriminating collapse loess is about 92.5%.