中文摘要：

本文的研究发现：内部控制质量的提高有助于抑制大股东资金占用；进一步的研究则发现，内控显著抑制大股东资金占用的现象，仅在低审计质量样本（事务所为非四大样本）中成立；在四大样本中，该结论并不成立。这说明，内部控制与外部审计之间存在一定的替代效应，在审计质量较低的环境下，内部控制所发挥的作用更为明显。因此，完善内部控制，对于审计市场尚不太成熟、审计质量普遍不太高的我国证券市场，就显得尤为重要。

英文摘要：

Our research finds that internal control can restrict control shareholder＇ tunnel and agency cost. Our research also finds that internal control＇s function of restricting control shareholder＇ tunnel would only comes into existence in the sample of low quality of audit. It means that there are a substituted relation between audit and internal control. For the reason, it is particularly important to reinforce internal control with the circumstances of lack of high quality audit.