集團企業因其股權及組織結構之特性，容易有盈餘管理之行為，若再透過委託不同會計師事務所查核其旗下子公司，則其盈餘管理行為可能愈不容易被發覺。本研究主要目的在探討集團企業委託同一和不同會計師事務所查核財務報表時，是否會影響其盈餘管理之行為。實證結果顯示，集團企業比非集團企業有更多盈餘管理之行為；此外，集團企業若委託不同大型會計師事務所查核其旗下子公司的財務報表時，亦會比委託大型事務所查核之非集團企業有更多盈餘管理之行為。而當集團企業委託同一事務所查核其旗下子公司時，相較於委託不同事務所查核，其向上盈餘管理之行為顯著較少，但是此效果亦僅限於委託大型事務所查核之集團企業。本文結果除彌補目前集團企業盈餘管理行為相關文獻之不足外，也對近期行政院金融監督管理委員會準備推動之集團企業「主查會計師制度」提供參考意涵。

Owing to their unique capital and organizational structures, the affiliated business groups tend to have more activities of earnings management. If they hire different CPA firms to audit their affiliated companies, their earnings management behavior may not be easily detected. The main purpose of the study is to examine whether or not earnings management behavior differs between companies with affiliated business groups audited by the same CPA firm and those audited by different CPA firms. Empirical results show that companies with affiliated business groups have higher scores in earnings management, compared to companies with no affiliated business groups. Furthermore, among companies with affiliated business groups, those audited by different big CPA firms show significantly more earnings management than those with no affiliated business groups audited by big CPA firms. Affiliated companies audited by the same CPA firm have significantly less upward earnings management than those audited by different CPA firms; however, this result only applies to big CPA firms. Findings of this study not only make incremental contributions to the existing documents in earnings management study on the affiliated business groups but also provide reference to the ”main auditing CPA system” for the affiliated business groups proposed recently by the Financial Supervisory Commission of the Executive Yuan.