為了因應查核報告的改革浪潮，以改善傳統查核報告溝通價值不足的問題，台灣上市(櫃)公司於2016年起提前適用新式查核報告，且會計師須從與治理單位溝通之事項中，選出當期查核最為重要的事項，並針對個別公司客製化關鍵查核事項段，希望能提供財報使用者更攸關的資訊。 本研究之目的係探討關鍵查核事項與權益資金成本之關聯性，分析揭露的項次數目與內容的可讀性，對於資訊價值的影響。實證結果發現，揭露關鍵查核事項會向使用者傳達不確定性，且揭露越多項次會降低資訊效果，因此要付出較高的權益資金成本，此外，當關鍵查核事項的可讀性越高，能改善資訊不對稱的情形，故能降低權益資金成本。;In order to respond the reformation of audit report to improve the insufficiency of information, the extended audit report will be implemented for the companies in Taiwan since 2016. Key audit matters are selected from matters communicated with governance as the most significant matters during the audit of financial statements of current period, and accountants will customize key audit matters depending on different situation of each firm to provide more relevant information to investors. The study examines the relationship between key audit matters and cost of equity, also analyzes the influence of the number and the readability of key audit matters on the informational value. The results show that key audit matters convey uncertainty to the users of financial statements, and that disclosing more key audit matters will decrease the value of communication, therefore, firms will have higher cost of equity. However, increasing the readability of key audit matters can reduce the information asymmetry so that firms will have lower cost of equity.