This book constitutes the refereed proceedings of the Third International Conference on Multimodal Interfaces, ICMI 2000, held in Beijing, China in October 2000. The 38 revised full papers and 48 poster papers presented in the book were carefully reviewed and selected from a total of 172 submissions. The papers are organized in topical sections on affective and perceptual computing; gesture recognition; face and facial expression detection, recognition and synthesis; multilingual interfaces and natural language understanding; speech processing and speaker detection; object motion, tracking and recognition; handwriting recognition; input devices; virtual and augmented reality; multimodal interfaces for wearable and mobile computing; sign languages and multimodal navigation; and multimodal integration and application systems.