Bamboo is known as multi-purposes plants and currently, has potentially used as wood substitution products. The demand for bamboo from industrial sector is even higher. Although many countries have practiced bamboo cultivation, in Indonesia Bamboo tends to be allowed to grow naturally and still lack of treatment. The threat of unsustainable exploitation can cause the decreasing of bamboo productivity and lead to its scarcity. The sustainable bamboo forest management system then emerged as a solution. But the knowledge of such system has not been transmitted massively among bamboo farmers and owners. This paper will discuss the transfer of knowledge on sustainable bamboo forest management using social capital as an approach. This paper uses data from research project conducted in 2018 to 2019, which is located in Ngada Regency, East Nusa Tenggara, Indonesia. The results indicated that social capitals such as trust, organizations, social networks, and norms or rules are embedded with social institutions that exist among community. This research shows that Sa’o and BUMDes could be the most potential media as a means on transferring knowledge about sustainable bamboo forest systems. Both can be used as an entry point for any actors to run a small-scale bamboo industry development program. However, there are some potential obstacles could be occurred during the process of knowledge transfer, such as in-group feeling among indigenous community, the assumption that bamboo is a social good, not an economic good, do not concerned with the commercialization of bamboo, the complexity of inheritance law in the customary (adat) system, and the involvement of adat elites in political practices related local elections.