This volume resulted from a conference held at Kyoto University and Nara Women's University (Japan) in commemoration of the late Professor Kiyoshi Oka, one of the most famous Japanese mathematicians. Included are 34 research and survey papers contributed by the invited lecturers and a letter written for the occasion by H. Cartan. Among the leading mathematicians who contributed to the volume are E. Bedford, S. Kobayashi, J. J. Kohn, and M. Kuranishi. The topics discussed include pseudoconvex domains, $bar{partial}$ analysis (including $L^2$ theory), the Bergman kernel, value distribution theory, hyperbolic manifolds, dynamical systems, infinite dimensional complex analysis, algebraic analysis, CR structure, singularity theory, algebraic geometry, and others. The book is suitable for advanced graduate students and research mathematicians interested in complex analysis, algebraic geometry, and complex geometry.