All universities must achieve legitimacy, as this is essential to attract students, staff, and resources, including funding. To achieve legitimacy in transnational higher education, universities must conform to the rules and belief systems in the host countries. Adopting a case study approach, this research aims to investigate the different institutional influences on three Chinese international branch campuses (IBCs) that operate in South East Asia. The institutional factors behind the strategies taken in establishing and operating such branch campuses are discussed, as well as the different legitimacy building strategies adopted to counteract the liability of foreignness in the host countries. It was found that legitimacy is established through three modes: legitimacy conformity, selective legitimacy conformity/nonconformity, and legitimacy creation, which are adopted according to the IBC's dependence on local resources and the strength of the institutional forces in the host country.