th We compiled this volume mostly from presentations at the 6 International Plant Cold Hardiness Seminar (PCHS) after consulting with Professor Tony H. H. Chen, Oregon State University, USA, Professor Pekka Heino, University of Helsinki, Finland, th and Dr. Gareth J. Warren, University of London, Surrey, UK. The 6 International PCHS was held at the Unitas Congress Center, Helsinki, Finland from July 1-5, 2001. There were 110 registered scientists at the serttinar representing 20 countries: Australia, Belgium, Canada, Chile, the Czech Republic, Denmark, Estonia, Finland, Gennany, Hungary, Iceland, Italy, Japan, Norway, Poland, Spain, Sweden, Taiwan, United Kingdom, and United States of America. The infonnation compiled represents the state of the art of research in phmt cold hardiness in tenns of gene regulation, gene expression, signal transduction, the physiology of cold hardiness and, ultimately, the genetic engineering for cold tolerant plants. The International PCHS was initiated in 1977 at the University of Minnesota, St. Paul, Minnesota. It has been traditionally held at 5-year intervals at various locations. th Because of the rapid advances of research in plant cold hardiness, attendees at the 6 meeting unanimously adopted a resolution to hold the seminar in 3-year intervals instead of 5 in the future. Consequently, the next seminar will be held in 2004 in Sapporo, Japan, and Professor Seizo Fujikawa from Hokkaido University will serve as the host.