The 7th Paci?c Asia Conference on Knowledge Discovery and Data Mining (PAKDD) was held from April 30 to May 2, 2003 in the Convention and Ex- bition Center (COEX), Seoul, Korea. The PAKDD conference is a major forum for academic researchers and industry practitioners in the Paci?c Asia region to share original research results and development experiences from di?erent KDD-related areas such as data mining, data warehousing, machine learning, databases, statistics, knowledge acquisition and discovery, data visualization, and knowledge-based systems. The conference was organized by the Advanced Information Technology Research Center (AITrc) at KAIST and the Statistical Research Center for Complex Systems (SRCCS) at Seoul National University. It was sponsored by the Korean Datamining Society (KDMS), the Korea Inf- mation Science Society (KISS), the United States Air Force O?ce of Scienti?c Research, the Asian O?ce of Aerospace Research & Development, and KAIST. It was held with cooperation from ACM’s Special Group on Knowledge Dis- very and Data Mining (SIGKDD).