This paper addresses the most prominent late imperial Chinese “Confucian physician”, Zhu Zhenheng (1281-1358), from a social history perspective, investigating how a local physician in Southern China arose to be a nationally acknowledged authority on medicine between the thirteenth and sixteenth centuries. Although Zhu and his “Danxi” school had been intensively explored by previous scholarship, this paper’s contribution lies in its meticulous reconstruction of the forming of “Danxi” mastership in scholarly medicine as a century-long historical process situated in changing social and political context of local Jiangnan (Yangzi Delta) region. Firstly, it unveils Zhu’s image as a powerful social and cultural authority in his hometown Wuzhou, by highlighting his leading participation in ancestral sacrifice activities of local families under the surname of “Zhu”, in tax revenue collection and judicial negotiation with local government, and in other “public” affairs. Secondly, it traces the expansion of this network of physicians, who identified themselves as Zhu’s medical disciples, from local Yangzi Delta to the Imperial Medical Bureau of the newly established Ming power. This evolving network, enhanced by the “master-disciple” connection, facilitated the social foundation of Danxi’s rise as the national master on medicine. Thirdly, it argues after the mid-fifteenth century, the idea of being a disciple of the Danxi school shifted from making personal connection with Zhu’s medical descendants to interpreting Zhu’s idea through textual production, which focused on a certain public and scholarly debate on “authentic” principle of “Danxi”. Enhanced by a flourishing commercial publishing industry from the late fifteenth century onward, this new scholarly style of textual production finally consolidated the “Danxi” school in late imperial Chinese medical tradition.