Abstract: This study is a case study that examines a nationwide and decade-long network of joint social organizations of disaster relief，focusing on the specific operational mechanisms of collaboration among heterogeneous social entities within society. The approach differs from the perspective of “understanding society in the light of the state”，as well as organizational cooperation studies under the general theory of organization. The study identifies three major players in the network： philanthropic foundations，provincial coordinating bodies acting as intermediaries， and grassroots volunteer organizations. These three components form a hierarchical network governance structure that effectively facilitates organizational collaboration. The characteristics of this hierarchical network governance mechanism lie in the following：the first-tier network unite the foundations and provincial coordinating bodies through a consensus on modern philanthropy；the second-tier network relies on the coordinating role of provincial bodies，which take on more responsibilities as agents，simplifying the requirements of modern philanthropic practices，easing the tension between modern philanthropic concepts and local volunteer culture，and thereby realizing the compatibility of the two and fostering the transformation of grassroots volunteer forces into modern philanthropic entities. Provincial coordinating bodies play a crucial role in sustaining the vitality of local networks by actively expanding resources and responding to the resource needs of grassroots organizations at the county level，which in turn enhance the functionality and efficiency of the overall network. The study concludes that the hierarchical network governance represents a unique form of horizontal connection among social organizations within the Chinese context，which can effectively unite diverse social forces，achieve social integration and is of great practical significance for social organisations to participate in governance. The finding challenges the assumption that social horizontal connections produce relatively independent society.

Key words: social organizations, collaborative network, hierarchical governance, provincial coordination organization