This book constitutes the thoroughly refereed post-proceedings of the Chinese Academy of Sciences Symposium on Data Mining and Knowledge Discovery CASDMKD 2004, held in Beijing, China in July 2004.The 25 revised full papers presented together with 3 invited keynote papers were carefully reviewed and selected from 60 submissions. The papers are organized in topical sections on data mining methodology, practical issues, data mining for bioinformatics, data mining applications, enterprise knowledge management, risk management, and integration of data mining and knowledge management.