This study provides a literature review of social capital in cooperatives. We integrate the social capital concept with cooperative lifecycle theory and describe the change of cooperative social capital along the lifecycle. We propose that cooperatives in different stages of the lifecycle are featured with different social capital levels. Cooperatives are supposed to enjoy a large stock of social capital in the early stages of the lifecycle. However, the level of social capital in cooperatives exhibits a trend of declining along the development of the organization. The decrease of social capital will lead to an imbalance of the social and economic attribute of cooperatives. The cooperative’s income rights structure must change accordingly. We argue that it is important for cooperatives to strategically maintain and develop the social capital over time. Otherwise, the comparative advantage of the cooperative form may disappear.