无实际控制人是重新审视董事异议投票行为的重要场景。以2007~2022年中国A股上市公司为样本，从董事会决策的视角，实证探讨无实际控制人对董事异议投票行为及其监督有效性的影响。研究发现，无实际控制人公司董事更有可能提出异议。机制检验表明，股权制衡度提高、董事会结构改善是无实际控制人影响董事异议投票行为的重要渠道。异质性分析中，在董事会成员专业多样性较高的情形下，董事异议投票行为更显著。进一步地，双无控制、非强势关联关系企业董事更倾向于投非赞成票，且无实际控制人企业董事投非赞成票提高了资本市场定价效率，发挥了应有的监督效果。

The absence of an actual controller is an important scenario for re-examining the behavior of directors’ dissenting votes. Taking Chinese A-share listed companies from 2007 to 2022 as samples, from the perspective of board decision-making, this study empirically explores the influence of directors’ dissenting voting behavior and the effectiveness of the supervision without actual controllers. Research has found that directors of companies without actual controllers are more likely to raise objections. Mechanism tests show that the improvement of equity balance and the enhancement of the board structure are important channels for directors’ dissenting voting behaviors without the influence of actual controllers. In the heterogeneity analysis, when the professional diversity of board members is relatively high, the behavior of directors’ dissenting voting is more significant. Furthermore, directors of enterprises without dual control or strong affiliated relationships are more inclined to cast non-approval votes, and the non-approval votes cast by directors of enterprises without actual controllers have improved the pricing efficiency of the capital market and exerted the due supervisory effect.