The extensive development of HCI technology has reached its limit due to diverse computing devices and human preferences. To deal with the problem, we need to actively and voluntarily integrate all-detected user's intents to deliver optimal results to the user on diverse computing environments. In traditional HCI, a user receives a valid response from a computer only if the user accurately transmits intention to the computer using a very refined expression consciously in a single way. In humancomputer cooperation (HCC) technology, a computer can understand intention of a user group using conscious input obtained by diverse input devices and types and unconscious responses obtained by physical response and environmental information through various wearable sensors. Through simple and intuitive inputs and interactive responses between a user and a computer, HCC technologies develop an interface which helps users to reach the clear results what users want. This special issue is soliciting high-quality technical papers addressing research achievements, practices and challenges for human-computer cooperation techniques. Original and research articles are solicited in all aspects of including theoretical studies, practical applications, new social technology and experimental prototypes.This special issue is soliciting high-quality technical papers addressing research practices and challenges in the areas of human-computer cooperation. It will reflect the state of the art of the computational methods, involving theory, algorithm, numerical simulation, error and uncertainty analysis and/or novel application of new processing B Byeong-Seok Shin