股權結構決定企業所有權的分配方式， 並影響決策與治理機制， 進而影響財務績效。既有的實證更指出，股權結構亦影響ESG（ 環境、社會與公司治理）表現。隨著全球永續發展趨勢，企業是否能透過良好ESG 表現提升績效，日益受到關注。因此，本研究探討ESG 表現是否在股權結構與財務績效之間發揮中介效果。研究以2 0 1 9 至2 0 2 3 年臺灣上市公司排除金融產業做為樣本， 採用PLS-SEM進行分析。結果顯示，股權結構對財務績效具有顯著正向影響，且部分透過ESG 表現發揮間接效果。尤其，外資對公司治理正向影響力最強，本國機構次之，大股東與內部人持股則可能削弱外部監督，限制ESG 投入，而政府持股亦具正向影響， 惟其影響程度相對有限。本研究不僅驗證ESG 表現的中介角色， 亦突顯多元化股權結構在促進企業永續與財務成果間的關鍵作用， 為企業在永續轉型時提供股權治理的方向建議， 亦有助於長期投資者、政策制定者與責任投資機構於資本配置與治理評估中做出更具策略性的決策。

The ownership structure determines how corporate ownership is distributed and influences decision-making and governance mechanisms, thereby affecting financial performance. Existing empirical evidence further indicates that ownership structure also impacts ESG (Environmental, Social, and Governance) performance. With the global trend toward sustainable development, increasing attention has been directed toward whether firms can enhance performance through strong ESG practices. Therefore, this study aims to examine the mediating role of ESG performance in the relationship between ownership structure and financial performance.<br>This study uses a sample of Taiwan-listed companies from 2019 to 2023, excluding firms in the financial industry, and employs Partial Least Squares Structural Equation Modeling (PLS-SEM) for empirical testing. The results show that ownership structure has a significant positive impact on financial performance, with part of the effect mediated through ESG performance. Specifically, foreign ownership exerts the strongest positive influence on corporate governance, followed by domestic institutional ownership. In contrast, greater ownership by large shareholders and insiders may weaken external oversight and constrain ESG investment. Government ownership also shows a positive but relatively limited impact. The findings confirm the mediating role of ESG performance and highlight the importance of a diversified ownership structure in promoting both corporate sustainability and financial outcomes. These results provide practical implications for firms undergoing sustainability transitions through ownership governance and offer strategic insights for long-term investors, policymakers, and responsible investment institutions in capital allocation and governance evaluation.