<p>Sino-foreign cooperative universities (SFCUs) have become an integral component of the Chinese higher education system. This research investigates how SFCUs establish legitimacy and strategically position themselves within a tightly regulated and highly competitive environment, employing a comparative case study of ten institutions. Drawing upon institutional theories, we utilize a four-dimensional legitimacy framework encompassing regulative, cognitive, moral, and pragmatic dimensions. Our analysis of official communications reveals that while all SFCUs build a common foundation on regulatory legitimacy, they employ four distinct logics to differentiate themselves across the other dimensions: a logic of global prestige, a logic of research power, a logic of strategic adaptation, and a logic of diplomatic mission. The findings highlight the complex interplay between institutional isomorphism and competitive differentiation, demonstrating how the value of a legitimacy claim is contingent on institutional characteristics and local context. This study advances the understanding of organizational legitimacy in transnational higher education and illuminates the strategic diversity within the understudied SFCU sector.</p>