This book constitutes the refereed proceedings of the 6th Asia Pacific Conference on Computer Human Interaction, APCHI 2004, held in Rotorua, New Zealand in June/July 2004. The 56 revised full papers and 13 revised short papers presented together with 10 short papers from a doctoral consortium track were carefully reviewed and selected for inclusion in the book. The topics addressed span the entire spectrum of HCI, including human factors and ergonomics, user interface tools and technologies, mobile and ubiquitous computing, visualization, augmented reality, collaborative systems, internationalization and cultural issues, etc.