本研究主要係在探討經過會計師查核的內部控制報告書是否會影響到分析師的公私有資訊精確度以及市場流動性。實證結果發現，當公司被視為具有重大內控缺失者，會造成分析師公有及私有資訊精確度下降，進而使得整體資訊環境的不確定性增加。本研究亦發現，當公司揭露內部控制缺失時，該公司在宣告期間會有較差的市場流動性以及較嚴重的資訊不對稱性。本研究更進一步將內控缺失區分成公司及會計層級內控缺失，結果發現有公司層級內控缺失的公司，相較於會計層級缺失者，會有較差的公有資訊精確度及市場流動性。最後，本研究發現，若公司下一年度有進行內部控制缺失修正時，會產生較高的公私有資訊精確度及較高的市場流動性。 / This dissertation extends prior research on internal control weaknesses (hereafter ICW) by examining the impact of internal control weakness and their remediation on information precision and market liquidity for firms filed Section 404 reports with the SEC. First, I find that the presence of ICW is associated with lower precisions of public and private information contained in analysts’ earnings forecasts, which in turn increase overall information uncertainty. Second, I find that market liquidity is significantly lower for ICW firms. Moreover, this dissertation provides evidence that firm-level control weaknesses have stronger impact on public information precision and market liquidity than account-specific control weaknesses. Finally, this dissertation suggests that ICW remediation firms have higher information precision and market liquidity, compared to non-remediation firms. My results are robust after controlling for the endogeneity problem and other sensitivity tests.