The photosynthetic fixation of carbon dioxide into organic compounds is mediated by the enzyme ribulose 1,S-bisphosphate (RuBP) carboxylase. The diversity of current research on this protein attests to its central role in biomass productivity, and suggests the importance of a timely and broadly based review. This Symposium was the first devoted exclusively to RuBP carboxylase and was attended by agronomists, plant physiologists, biochemists, molecular biologists, and crystallographers. Special efforts were made to involve young scientists in addition to established investigators. It is a pleasure to acknowledge financial support provided by the Department of Energy, the United States Department of Agricul ture, and the National Science Foundation, and the valued assistance of agency representatives, Drs. Joe Key, Robert Rabson, Elijah Romanoff, and Donald Senich. Thanks are due to Mrs. Margaret Dienes, without whose editorial skills this volume could not have been produced, and to Mrs. Helen Kondratuk as Symposium Coordinator. Finally, we wish to record our indebtedness to Dr. Alexander Hollaender for his tireless efforts in support of all aspects of this Symposium.