This research investigated the trust as an important underlying factor in understanding how the relationships between auditor and client’s management are established and developed between179 persons of the members of IACPA as senior auditor, supervisor, senior supervisor, and partner or manager of the audit firm, who have the ability to assess audit risks and make decision to trust or not.There are different factors affecting auditor’s trust on client’s management and evidences presented by them. But this research investigated the effects of clients’ management characterestics as a very important factor.As there was no standard questionnaire to conduct the research a questionnaire was designed by considering the nature and subject of the research and based on the results of prior researches. By using this questionnaire, the type of impact (increase, decrease or no impact) and the importance (very low, low, medium, high or very high) of 18 items of trustee's characteristics (client's management) under 5 groups (classification): ability of management, benevolence of management, management compliance with ethical norms, accountability of management, and reputation of management on auditor's trust on client’s management and evidences presented by them have been investigated. The collected data was analyzed by applying Wilcoxon Signed Ranks Test, and One-Sample T Test. The results of analyzing auditors’ opinion indicate that management compliance with ethical norms, ability of management, management accountability, and management reputation are respectively the most important factors affecting auditors’ trust.