This book constitutes the refereed post-proceedings of the 13th International Conference on AI, Simulation, and Planning in High Autonomy Systems, AIS 2004, held in Jeju Island, Korea in October 2004. The 74 revised full papers presented together with 2 invited keynote papers were carefully reviewed and selected from 170 submissions; after the conference, the papers went through another round of revision. The papers are organized in topical sections on modeling and simulation methodologies, intelligent control, computer and network security, HLA and simulator interoperation, manufacturing, agent-based modeling, DEVS modeling and simulation, parallel and distributed modeling and simulation, mobile computer networks, Web-based simulation and natural systems, modeling and simulation environments, AI and simulation, component-based modeling, watermarking and semantics, graphics, visualization and animation, and business modeling.