本研究探討台灣會計師公費揭露的市場反應，並以累計異常報酬（CAR）來衡量市場反應。第一階段針對是否揭露會計師公費研究其不同的反應；第二階段再將有揭露會計師公費的公司區分為主動揭露與被動揭露，並探討是否會造成不同的影響；第三階段更進一步將被動揭露的公司依其所符合的法規揭露原因再做細分，特別探討因為非審計公費過高而揭露公費者之市場反應。 研究結果發現，相較於不揭露會計師公費的公司，市場對於有揭露會計師公費資訊的公司會給予較正面的反應；其中，有揭露會計師公費的公司，若屬於主動揭露，市場更是會給予正面的肯定；相反的，有揭露會計師公費的公司，若是因非審計公費達審計公費之四分之一以上者而被動揭露者，市場會對此公司之會計師之獨立性有所懷疑，故給予負面的反應。可見會計師公費的資訊對投資大眾而言確實是一項有意義且重要的資訊。本研究並加入公司治理的相關變數，研究結果發現，若公司之治理程度較差，但「有揭露」會計師公費資訊者，投資大眾會給予正面的反應，此外，相對於被動揭露者，市場對於「主動揭露」之公司會給予更正面的肯定。另一方面，若公司之治理程度較佳，但其揭露原因是屬於非審計公費達審計公費四分之一以上而被動揭露者，市場會對會計師獨立性有所質疑，故對於此種公司仍給予負面的反應。 / This study attempts to examine audit fee disclosure and market reactions. We use Cumulative Abnormal Returns to measure market reactions. First, we analyze whether audit fee disclosure has any market reactions at all. Second, we divide the samples into voluntary disclosure and forced disclosure groups. Third, we make further segmentation from the forced disclosure group according to their disclosure reasons, and specially focus on the disclosure reason of high non-audit fees. We find that market reactions are significantly more positive for firms with audit fee disclosures than for firms without fee disclosure. Market reactions are also significantly better for firms with voluntary disclosure than the forced disclosure group. In contrast, market reactions are significantly lower for firms which disclose audit fees due to high levels of non-audit fees. Our evidence supports that audit fee is a piece of useful and important information to investors. Additionally, we include corporate governance variables in the analysis. We find that when firms’ corporate governance is not good, if they choose to disclose audit fee voluntarily, the market responds with positive reactions. In contrast, if a firm’s corporate governance is quite good but discloses audit fees due to high levels of non-audit fee, the market then reacts with negative returns.