Mohammad Hamed KhanMohammadi - Assistant Professor of Accounting, Department of Accounting, Damavand Branch, Islamic Azad University,Damavand, Iran
Ali Akbar Arbabian - Department of Accounting and Management, Shahid Beheshti University, Tehran, Iran
Tooran ShiriDoyj - Graduated from M.A, Department of Accounting, Damavand Science and Research Branch, Islamic AzadUniversity, Damavand, Iran

This research aims to examine the impact of audit quality (auditor’s quality evaluation, auditor size,auditor industry specialization, and auditor tenure) on Iran capital market. The result of the analysis of1140 years of the company during 2006-2015 has shown that there is a significant negative relationshipbetween the auditor expertise and auditor tenure. Although the negative relationship between all of thecriteria of audit quality and cost of capital is not confirmed, it cannot be claimed that high audit qualitydoes not cause reduction in cost of capital in Iran capital market.

Audit Quality, Cost of Capital, Auditor’s Quality Evaluation, Auditor Size, Auditor Expertise, Auditor tenure