Agents and multi-agent systems are related to a modern software paradigm which has long been recognized as a promising technology for constructing autonomous, complex and intelligent systems. The topics covered in this volume include agent-oriented software engineering, agent co-operation, co- ordination, negotiation, organization and communication, distributed problem solving, multi-agent communities, rational and clustering agents, learning paradigms, agent cognitive models, and heterogenous multi-agent environments. The volume highlights new trends and challenges in agent and multi-agent research and includes 30 papers classified in five specific topics: Modeling and logic agents, Knowledge based agent systems, Cognitive and cooperative multi-agent systems, Agent-based Modeling and Simulation, and Learning Paradigms and Applications: