The level of clients accounting information comparability affects Certified Public Accountants（CPAs）’ professional judgment，and thus having an impact on the corresponding decisions they make.Taking A share listed companies in Shanghai and Shenzhen from 2006 to 2014 as a sample，this paper analyzes the impact of accounting information comparability on CPAs audit decisions.The results of the study show that the weaker the comparability of accounting information is，the more likely the CPA firms change.Further research shows that among the clients who changed accounting firms，the weaker the comparability of accounting information is，the higher the audit fee becomes，and the more likely it obtains the modified audit opinion.These results above help us better understand and evaluate the audit decisions made by CPAs，and provide an incremental experience for us to study the factors that affect audit decisions.