Abstract: According to the resource dependence theory, resources serve as the basis for enterprises to undertake economies of scope, while social relationship networks constitute an important channel for enterprises to acquire resources. On this basis, with non-financial listed companies in Shanghai and Shenzhen A-share markets from 2008 to 2023 as the research subjects, an empirical test was conducted to examine the influence of the supply chain social relationship network with shareholders as the hub on the diversified operations of enterprises. The research reveals that common shareholders in the supply chain can significantly facilitate the diversified operations of enterprises, and the promotion effect on related diversified operations is more pronounced. The influencing channel lies in the fact that common shareholders of the supply chain provide the information and financial resources necessary for enterprises to engage in diversified operations. The heterogeneity analysis indicates that when the geographical distance between supply chain enterprises is shorter, the degree of marketization in the location of enterprises is higher, and the redundant resources are scarcer, the facilitating effect of common shareholders of the supply chain on diversified operations, especially on related diversified operations, is stronger. The exploratory analysis discovers that when common shareholders of the supply chain hold enterprises in the same industry, the holding direction is the upstream enterprise, and the holdings are symmetrical, the facilitating effect of common shareholders of the supply chain on the diversified operations of enterprises, particularly on related diversified operations, is stronger. Accordingly, enterprises should actively establish common shareholder linkages with upstream and downstream partners in the supply chain, prioritize connections with enterprises in the same industry and upstream suply chain, build two-way symmetric equity ties, and leverage the information and capital advantages brought by common supply chain shareholders to better realize economies of scope.

Key words: common shareholders in the supply chain, corporate diversified operations, types of diversified operations, information resources, financial resources