With the rapid development of economic globalization, keeping the global supply chains sustainable is becoming increasingly important in improving supply chain performance and firm value. To fully understand the role of the supply chain relationship, it is necessary to comprehensively assess different characteristics of supply chain partnership in achieving sustainability goals. This study explores the implication of concentrated supply-chain partnership on loan features. Using a sample of Chinese-listed firms, we find that concentrated customer or supplier bases positively influence loan features, including loan size, loan maturity, and loan cost. We propose that concentrated customer and supplier bases influence the loan features through different mediators. Through mediating analysis, concentrated customer bases affect loan features through better corporate governance and lower operational risk, and concentrated supplier bases through lower operational cost and longer accounts payable cycle. The benefit of a concentrated chain partnership is more pronounced when customers or suppliers have a greater certification role, less uncertainty, and stronger geographical advantage. The results are robust to instrumental variable analysis, propensity-matched analysis, and alternative measures of chain partnership concentration. Findings in this study have important implications for understanding the sustainable supply-chain partnership management and loan decisions of banks in an emerging market.