Duan, J. and Wiggins, S. Lagrangian Transport and Chaos in the Near Wake of a Cylinder in the Time-Periodic Regime: A Dynamical Systems Approach (4427K, PostScript) ABSTRACT. In this paper we study Lagrangian transport in the near wake of a cylinder in the time-periodic regime. We use ideas and methods from transport theory in dynamical systems to describe and quantify transport in the near wake. We numerically solve the Navier-Stokes equations for the velocity field and apply these methods to the resulting numerical representation of the velocity field. We show that dynamical systems methods can be used in conjunction with computational fluid dynamics methods to give very detailed and quantitative information about Lagrangian transport.