Using a sample of listed companies in Taiwan over the period of 2005-2007, we investigate the relationship between internal control weaknesses and accrual quality, and the moderating effect of independent directors and supervisors. After controlling for voluntary disclosure of weakness internal control self-selection bias, we find that internal control weaknesses are positively associated with the magnitude of abnormal accruals. The results imply that the more control weaknesses, the lower accrual quality. In addition, the independent directors and supervisors has positive moderating effect on the relationship between weaknesses of internal control and accrual quality, improve accrual quality. Our findings provide evidence that the effect of internal control weaknesses on accrual quality is conditional on the existence independent directors and supervisors.