Many research papers have recognized the importance of knowledge management (KM) and knowledge sharing (KS) in supporting innovation an organization. They agree that knowledge is a principal factor behind an enterprise’s key critical success. However, some scholars have revealed that community of practice (COP) is a critical aspect and component for implementing knowledge management in an organization because it helps to facilitate sharing or exchanging of collected knowledge and improve the organizational performance. In this research, is collect data from the information technology firms in North Taiwan to analyze the relationship between communities of practice, social capital and individual innovation. In this viewpoint we studying interpersonal relationships and social trust is effect to individual innovation in the communities of practice and results showed social trust the impact on individual innovation is very significant, we observe「trust」of the social capital are important for knowledge sharing to individual innovation and interaction in the communities of practice.