The past decade in e-commerce will be remembered as one in which age- mediated electronic commerce technology became a reality. The evolution from electronic data interchange technology to electronic marketplaces brought e-commerce to the masses. Yet it was accompanied by numerous challenges - tributed to the exponentialincreasein the e?orts requiredfor searchingandp- cessing information as well as coordinating with the di?erent parties involved. Theintroductionof autonomousagentsin e-commerce,enabling agent-mediated trading, holds the promise of bridging this gap, by facilitating ?exible, faster, less labor-intensiveandhighly competitive commerce. Using agents,e-commerce nowgoesbeyondmerelyeliminatingthemediatorsinthetraditionalprocessand o?ersadynamic set oftechnologies,integratedapplicationsand multi-enterprise business processes that link enterprises together. Consequently, the focus of - search in the area of e-commerce is now on technologies for online advertising, searching, negotiating, ordering, delivering, paying, using, and servicing. No- days, the application of agents in e-commerce is well recognized as one of the fastest-growing and most exciting areas of computer science. This volume presents some of the recent advances in research on designing trading agents and mechanisms for agent-mediated electronic commerce. It is built around a collection of articles initially presented at two highly respected international workshops held in the summer of 2009. The ?rst is the 11th - ternational Workshop on Agent-Mediated Electronic Commerce (AMEC 2009) collocated with the AAMAS 2009 conference held in Budapest, Hungary. The second is the 2009 Workshop on Trading Agent Design and Analysis (TADA 2009) collocated with the IJCAI 2009 conference held in Pasadena, California, USA.