Knowledge Representation and Reasoning (KRR) is an exciting, well-established field of research. In KRR a fundamental assumption is that an agent's knowledge is explicitly represented in a declatative form, suitable for processing by dedicated reasoning engines. This assumption, that much of what an agent deals with is knowledge-based, is common in many modern intelligent systems. Consequently, KRR has contributed to the theory and practice of various areas in AI, such as automated planning, natural language understanding, among others, as well as to fields beyond AI, including databases, verification, and software engineering. In recent years KRR has contributed to new and emerging fields including the semantic web, computational biology, and the development of software agents. The KR conference series is a leading forum for timely in-depth presentation of progress in the theory and principles underlying the representation and computational management of knowledge. KR will be a forum for the exchange and discussion of new ideas, issues, and results on the principles and practice of KRR.