At present, social capital plays an important role in promoting cooperation among channel members. However, the research on the effect of social capital on corporate performance in channel relationships has not yet reached a consensus. In order to fill the gap, based on the channel relationship perspective, it explores the role of two dimensions of social capital (i.e. structural social capital and relational social capital) on strategic performance. By introducing two median variables of knowledge redundancy and common problem solving, it establishes the relationship model between social capital, median variables and strategic performance. Based on the data collected from distributors of Chinese computers and computer components firms, the empirical findings show that structural social capital and relational social capital enhance strategic performance by promoting knowledge redundancy and joint problem solving. The conclusions expand the research on channel relationship management and social capital, and provide helpful implications for managerial practice.