The purpose of this study was to examine the effect of physical fitness improvement program on work intensity of persons with Down syndrome. For this, 8 adults with Down syndrome participated in program and were evaluated. The physical fitness improvement program consisted of grasp, lifting, carrying exercise for 12 weeks, 1 day a week for 2 hours per session. Compared with pre-program conditions, participants in program improved significantly in right grasp power, lifting ability but there was not significant improvement in carrying ability. In view of work intensity, work intensity level of two subjects was changed from average to hard in lifting. One subject was changed from very light to average and two subjects was changed from light to average in carrying. This results suggested that physical fitness improvement program was helpful for promotion the intensity of adults with Down syndrome.