中文摘要：

机构投资者对自愿性信息披露的影响机理是已有研究较少涉及的一个主题。本文在分析机构投资者对自愿性信息披露影响机理的基础上．率先比较研究了稳定型机构投资者和交易型机构投资者的不同作用机制。并进一步探索了机构投资者与其所处股权环境的交互作用对自愿性信息披露的影响。研究发现，机构投资者整体对自愿性信息披露呈显著负向影响，但稳定型机构投资者持股比例能显著提升自愿性信息披露程度。在股权较为集中时，机构投资者更倾向于对自愿性信息披露程度产生正面影响．股权集中且机构投资者为稳定型时，机构投资者持股比例对自愿性信息披露的正面影响更大。本文的研究结论为理解机构投资者的治理角色提供了新的思路和证据。同时有利于加深对自愿性信息披露的理解和认识。

英文摘要：

It is less of a main steam research topic to discuss the influence of institutional investors on corporate voluntary disclosure. This paper explores the influence mechanism between institutional investors and corporate voluntary disclosure. We make a comparative study according to the feature of institutional investor, such as long-term investors and short-term investors. Moreover, the interaction effect between equity characteristic and institutional investor on voluntary disclosure is also explored. We find that the share ratio held by institutional investor is negatively related to the voluntary disclosure level. But long-term institutional investors can improve voluntary disclosure quality. What＇s more, this impact is stronger when the equity characteristic tends to be concentrated and the institutional investor reveals to be long-term. Our paper makes a contribution to the institutional investors＇ role in corporate governance, and also deepens the understanding of voluntary disclosure.