But some other studies (Francis, 2004) examined the relation between the fees paid to auditors for audit and non-audit services during the year of 2001 by using pooled sample contains 3,133 unique firms in the United States within 1 year before and 1 year after a firm’s first disclosure of fees paid to auditors, the study shows that the auditor has an incentive to provide a high quality of audit work to preserve his reputation, as the client fees are a small proportion from the total income of the audit firm. (Chung, 2004) A multivariate regression analyses are used for testing a sample consists of Canadian firms listed on the Toronto Stock Exchange from 2002 to 2004 to study the impact of the limited auditor tenure on earnings, and thus audit quality by taking advantage of the unique audit regulations that govern the listed firms in Korea, by examining how discretionary accruals, a measure of earnings quality drawn from prior literature, vary around an event that imposed a limit on the length of the auditor-client relationship via the auditor designation requirement for Korean firms likely to manage earnings. The study found that limiting the length of the auditor-client relationship will be more motivating for auditors to maintain independence as it will improve the audit quality, which will provide more incentives to resist management pressures and thus holds firms from manipulating earnings. (Cameran et al., 2005) have studied the effect of the auditor engagement period on the quality of audit. To gather data, auditors have been appointed for a 3-year period engagement that can be renewed twice up to 9 years of engagement. Found that the auditor’s conservatism increases in the last 3-year period, the last one before the mandatory rotation, as well-known (Basu, 1997) model on timely loss recognition has confirmed. They have also hired earnings response coefficients as a proxy to measure investors‟ perception of audit quality, which have showed audit quality perception increase in the last 3-year period.