Opinion about the subject of a financial report makes the public accounting or auditor to be an important profesion. The auditor considers the decisions regarding opinions in the audit report whether or not the material of a commission is influenced by the professionalism and experience of the auditor. Previous research revealed that there were other factors that could weaken and strengthen the direct influence of auditor professionalism and auditor experience on materiality levels, namely professional ethics & client credibility. The number of samples in this study were 86 auditors. The sampling technique uses saturated samples. The number of respondents who filled in completely and returned the results of the questionnaire was 74 auditors. The analysis technique used is MRA. The test results show that (1) professional ethics is not able to moderate the influence of professionalism on the consideration of materiality levels, (2) professional ethics reinforces the experience of the auditor on consideration of materiality levels, (3) client credibility strengthens the influence of professionalism and auditor experience on materiality.