The formation of collaborations between corporations, nonprofits and governments is becoming an increasingly adopted way for corporations to address social problems. In this paper, collaborations that attempt to solve social problems are defined social collaboration. While existing research on social collaboration has explored the antecedents of collaboration formation and the successful factors of collaboration management, there is little research on impact of social collaboration on change in participating organizations' cognition and behavior. The purpose of this paper is to explore such impact of social collaboration on participating organizations. Especially, this paper focuses on changing process in participating organizations' cognition and behavior about social problems through social collaboration. This paper proposes the framework for above issues based on the previous studies on interorganizational learning theory and on social collaboration. Then, this paper conducted a case study on social collaboration. The case is that recycling business of textile products by TEIJIN FIBERS and FLANDRE. The results indicate that participating organization (FLANDRE) changed own cognition and behavior about waste disposal problems and recycling problems that have become a crucial social problems in the textile industry through learning these problems within collaboration and sharing the social mission of TEIJIN FIBERS. Finally, some key theoretical implications for research on social collaboration and limitations of this paper are discussed.