This volume presents the results of a NATO Advanced Study Institute on Dynamics of Infinite Dimensional Systems, held at the Instituto Superior Tecnico, Lisbon, Portugal, May 19-24, 1986. In recent years several research workers have considered partial differential equations and functional differential equations as dynamical systems on function spaces. Such approaches have led to the formulation of more theoretical problems that need to be investigated. In the applications, the theoretical ideas have contributed significantly to a better understanding of phenomena that have been experimentally and computationally observed. The investigators of this development come from different backgrounds - some from classical partial differential equations, some from classical ordinary differential equations and some interested in specific applications. Each group has special ideas and often these ideas have not been transmitted from one group to another. The purpose of this NATO Institute was to bring together research workers from these various areas. It provided a soundboard for the impact of the ideas of each respective discipline.