中文摘要：

论文以中国深沪两市A股非金融类上市公司2001—2005年跨越多个年度的大样本数据为基础，实证分析了股权集中背号下大股东持股及其他治理机制对公司价值的影响。结果表明，大股东持股比例对公司价值的影响具有区间特征，两者间呈现出一种“N”型的三次曲线关系。且本研究验证了前人的研究结论，公司价值与大股东控制权与所有权的分离度负相关，而与股权结构的制衡水平正相关。此外，与现有的理论预期和研究结论完全相反，本研究发现公司价值与独立董事比例显著负相关。

英文摘要：

Based on the cross-section data of A-share non-financial listed companies in China from year 2001 to 2005, this paper investigates the relationship between large shareholdings and firm value, as measured by Tobin＇s Q. We find evidence of a significant non-monotonic relationship. Tobin＇s Q first increases, then declines, and finally rises as large shareholdings rise. And we corroborate previous findings that the separation of control rights and cash-flow rights reduces firm value, and the ownership structure with multiple large shareholders increases firm value. However, contrast to existing theoretical expectation and previous findings, we find evidence of a significant negative relationship between the proportion of independent directors and firm value.