近年因台灣發生一連串食安、工安及環境污染事件，政府開始積極推動企業社會責任的落實，以期望透過企業社會責任報告書的揭露，來提高企業的透明度與當責性，以降低企業管理當局與社會大眾、外部投資者等之間資訊不對稱的情形。本研究以2013至2016年之台灣上市櫃公司為研究對象，檢視企業社會責任的揭露與權益資金成本之關聯性，在控制了公司規模、負債比率、淨值市價比、法人持股比率、獲利能力、產業別及年度別等預期會影響權益資金成本的變數後，實證結果顯示，企業社會責任報告書之揭露及強制性揭露企業社會責任報告書與權益資金成本皆呈顯著負相關，且若報告書有經第三方確信會增強其效果，但自願揭露企業社會責任報告書會減弱與權益資金成本的負相關，若強制前已自願揭露企業社會責任報告書會增強與權益資金成本之負相關。強制性揭露企業社會責任報告書對權益資金成本之影響效果大於自願揭露的效果。被政府強制規範揭露且強制後第一次揭露企業社會責任報告書之公司，其強制前後的權益資金成本沒有顯著的變化。 In recent years, a series of food, safety and environmental pollution incidents have occurred in Taiwan. The government began to actively promote the implementation of corporate social responsibility. In order to promote the disclosure of corporate social responsibility report to improve the transparency and accountability of enterprises to reduce the enterprise management and the public, external investors and other information asymmetry between the situations.This study focuses on enterprises registered in the public stocking market between 2013 and 2016 in Taiwan. In order to examined the relationship between the disclosure of corporate social responsibility and the cost of equity capital. In the control of the company's size, debt ratio, book to market ratio, institutional investors holding rate, profitability, industry, yearly. The empirical results indicated that there is a significant negative correlation between the disclosure of corporate social responsibility report and the mandatory disclosure of corporate social responsibility report and the cost of equity capital. The corporate social responsibility report has been assured by a third party will enhance its effectiveness, but voluntarily exposing the corporate social responsibility report will be less negative correlation with the cost of equity capital. If voluntary disclosure of corporate social responsibility reports before mandatory will increase the negative correlation with equity capital costs. Mandatory disclosure of corporate social responsibility report on the impact of the cost of equity capital effect is greater than the effect of voluntary disclosure. The corporate social responsibility report disclosure had been mandated and for the first time, there is no significant change in the cost of equity capital before and after enforcement.