Abstract:In the context of the Chinese government's strategy for sustainable development, the study of sustainable supply chain management (SSCM) for enterprises has important practical significance. Drawing data from 172 Chinese firms, the model studied the moderating role of firm size on the SSCM practices and the sustainable performance of the firms (economic, environmental, and social), using hierarchical regression analysis on SPSS 22.0. The results suggest that SSCM practices and firm size are positively related to the firm's environmental and social performance. Firm size moderates the effect of SSCM practices on economic performance. Additionally, SSCM internal practices have a significant positive impact on the economic performance of large enterprises, but not so much on the economic performance of the Small and medium enterprises(SMEs). This paper proposes a comprehensive SSCM practice performance model that identifies firm size as a moderating role. Through research on the moderating effect of firm size, the implementation and recommendation of SSCM for different firm size are given.