在審計市場競爭不斷加劇之下，採取產業專業化之產品差異化服務會計師事務所通常為提升競爭優勢並留住客戶重要策略之一。本研究之主要目的係從審計市場供給面角度來探討不同規模會計師事務所客戶業別集中度與審計公費(含財務簽證與稅務簽證公費)之關聯性。以2002-2011年行政院金融監督管理委員會「會計師事務所服務業調查報告」之公開資料庫進行分析，共得7,028個事務所-年樣本數。主要研究發現，就審計公費而言，整體會計師事務所客戶業別集中度對整體審計公費呈現著正向顯著之影響，尤以單獨開業事務所呈顯著正向關聯。進一步觀察，財簽公費方面，中大型會計師事務所客戶業別集中度對財簽公費則呈現負向顯著之影響，推測係因規模經濟效果，致審計公費較低。而稅簽公費方面，則結果相當一致性，即會計師事務所客戶業別愈集中，所獲取之稅簽公費亦愈高。最後，本研究亦進行若干敏感性測試，顯示上述實證結果具相當之穩定性。本文研究結果除可供審計公費訂價實務管理者做參考外，或能填補審計公費文獻的部份缺口。 Due to the increasingly fierce competition in audit market, service differentiation becomes one of the most important strategies to retain existing clients and enhance competitiveness for CPA firms. The analysis is focused on the association between client-industry concentrations for different sizes of CPA firms and fees (including audit fees and non-audit tax fees) from the supply-side perspective of the audit market. Empirical data obtained from 2002 to 2011 Survey Report of Audit Firms in Taiwan, published by the Financial Supervisory Commission, Executive Yuan generate 7,028 CPA firms as samples per year. The main findings are as follows: a significant positive correlation between client-industry concentrations and audit fees exists among CPA firms, especially among sole-proprietor CPA firms. According to the findings, a significant negative correlation between client-industry concentrations and audit fees exists among middle to large CPA firms, and the reason for the low audit fee is assumed to be the effect of scale economies; however, the correlation between client-industry concentrations and non-audit tax fees is positive which means CPA firms get higher non-audit tax fees through client-industry concentrations. Finally, this paper conducts several sensitivity analyses which show the stability of aforementioned empirical results. These research results can not only be used as a reference aid to practical management in audit pricing, but also be used to fill the insufficiency of literature studying in this area.