This book is a fully post-process the referee of the International Workshop on Trading Agent Design together and Analysis, TADA 2006, and on Agent Mediated Electronic Commerce, AMEC VIII 2006, held in Hakodate, Japan, in May 2006 as an event related to AAMAS 2006 , International Conference of the 5th Joint Autonomous Agents and multiagent systems. 17 revised full papers presented were carefully selected from presentations made at the workshop and include documents from the annual TAC tournament whose purpose is to stimulate research in trading agents and market mechanisms by providing a platform for agents competing in a market scenario is well defined.