本研究旨在從會計師任期與審計品質之關聯性，探討國內實施連續五年簽證之會計師應予強制所內輸調政策之良窳。本研究以異常應計作為計品質之衡量指標，分析長期查核簽是否對會計師獨立造成不利影響，進而有損於計品質。實證結果發現，隨著會計師任期的增加，審計品質並沒有顯著變差。相反的，長會計師任期反而能美制管理當局盈餘管理的彈性，而且不論是在管理當局操弄盈餘增加或向下操弄盈餘，會計師任期越長皆越能抑制管理當局盈餘管理的行為，該實證結論經許多敏感性測試後依然成立，相當具有穩定性。

This study investigates the relations between auditor tenure and audit quality. Our study is motivated by the regulator’s rule to call for “mandatory auditor rotation.” We use abnormal accruals as proxies for audit quality to examine whether extended tenure impairs auditor’s independence and results in audit quality reduced. The empirical results indicate that , under the current voluntary rotation regime in Taiwan, audit quality does not deteriorate over time as the auditor-client relationship lengthens. In opposition to the opinion of regulator in audit tenure, we do find that absolute abnormal accruals decline with auditor tenure. In other words, longer audit tenure constrains managerial discretions with accounting accruals, whether income-increasing or income-decreasing manipulations. These results are robust to several sensitivity analyses.