The purpose of this case is to find effectiveness of improvement of cognitive function with head injury patients through Computer-Assisted Cognitive Rehabilitation(CACR) program within various training programs. The subjects were three inpatient persons with head injury on Rehabilitation Hospital in Yonsei University and aged 28 and 14 and 2 woman and another man. It was used PSS CogRehab program during 15 days. Cognition, perception and activities of daily living(ADL) were compared pre-CACR with post-CACR by LOTCA, MVPT and MBI. According to this case study, in spite of short-term period, the subjects had changed of performance skills of cognition, perception and activities of daily living. Results were as follows : 1. LOTCA score of 3 cases showed increasing change after CACR performance, especially perception and visuoperception organization were increased. 2. Raw score was increased and processing time was controlled adjustable of MVPT within 3 cases. 3. MBI score of 3 cases were improved, especially dressing, feeding and toileting were improved each one step.