中文摘要：

本文通过构造分类和综合的外部治理水平，基于重污染上市公司的经验数据，考察了外部治理在环境信息披露和股权融资成本关系中的作用。研究发现，外部治理水平越高，企业环境信息披露质量越高，环境信息披露质量与股权融资成本显著负相关，行业监管法律水平、政府环境监管水平、政府环境补贴、媒体监督以及外部治理水平的提高，可以显著提升环境信息披露对降低股权融资成本的积极作用。进一步研究说明，外部主体对货币型环境信息与股权融资成本关系的治理效果更为显著。

英文摘要：

In this article, we use Shanghai ＇A-share＇ listed compa- nies in heavy polluting industry as the research object from 2009 to 2013. By constructing the classification and comprehensive external governance, we set up a index of external governance external gov- ernance from the five following aspects： industry environmental regulatory, government environmental regulators, environmental subsidies, media monitoring and competitive level within industry. The paper examines the role of external governance in environ- mental information disclosure and equity financing. We find that the higher the level of external governance, the higher the quality of corporate environmental disclosure, the environmental informa- tion disclosure quality and equity financing costs has a significant negative relationship, that means when the level of environmental information disclosure quality goes higher, the equity financing costs becomes lower. The enhancing the level of external gover- nance, industry regulatory, government environmental regulators, environmental subsidies and media monitoring strengthen the pos- itive impact of environmental information disclosure to reduce the cost of equity financing. We classify the environmental information into three aspects： disclosure of information to fulfill the environ- mental responsibility, environmental destruction and environmental responsibility information not fulfilled, further analysis shows that the role of external governance which promote the relationship be- tween financial environmental information and equity financing costs is better than non-financial environmental information. The paper makes up the deficiencies for single research of external gov- ernance from the governmental or social perspective, and contrib- utes to the field of the external environment governance with incre- mental supplement. Furthermore, we explore the effect of external governance on environmental information disclosure and cost of equity financing, and extent the traditional internal fact