Because the lifestyle changes now, people spend most time to work and have no time for exercise. According to the Department of Health, Executive Yuan, about 46% people of Taiwan have no exercise habits. As technology improvement, social network is becoming popular. So we design a web service, NTUFit. , that combine with goal-directly and social excitation to help user have a regular exercise behavior. In this service, user have to record their exercise and system will remind user to exercise. In social excitation, every users can see each other’s exercise behavior and give some comment or encouragement.