Trend analysis of CPA firms’ service mix over time indicates that auditors in South Korea have focused more attention on generating their revenues from the provision of their non-audit services than the traditional auditing revenue. Therefore, this study empirically investigates the impact of change in CPA firms’ service mix over time on auditor independence. The main results from this study are summarized as follows. First, in the estimation model with total capacity for damage divided by total statutory audit revenue as an dependent variable, those CPA firms with higher proportion of revenue from management advisory and other services are likely to accumulate a higher level of deep pockets against prospective damage lawsuits, and maintain higher level of auditor independence based on their strong financial strength. Furthermore, those CPA firms with higher proportion of certified public accountants that are owners tend to be passive in building up their strong deep pockets, which results in being detrimental to their auditor independence. Second, in the estimation model with total capacity for damage per each audit performed as an dependent variable, those CPA firms with higher proportion of management advisory and other service revenues earned from their audit clients are more likely to harm their auditor independence than other CPA firms.