This book constitutes the refereed proceedings of the First International Symposium on Computational and Information Science, CIS 2004, held in Shanghai, China in December 2004.The 190 revised papers presented were carefully reviewed and selected from 450 submissions. The papers address virtually all computational and algorithmic aspects in various sciences, mathematics, and engineering as well as data and information engineering. The papers are organized in four main parts on high performance computing and algorithms, computational modeling and simulation, bioinformatics and medical informatics, and data engineering and information science.