This study is conducted to investigate the relationship between auditor's specialization with information quality and investment efficiency. The purpose of this study is to determine the relationship between auditor's specialization in industry with information quality and investment efficiency. The temporal domain of this research is from the beginning of 2009 to the end of 2016. Since the results of this research can be used in developing laws and regulations of stock exchange, it is an applied research. Also, since this research seeks to find the relationship between several variables, it is a correlation type and its methodology is a comparative type. The statistical population in this research is 404 companies listed in Ajman Stock Exchange. The sampling method is systematic elimination that 84 companies were selected as sample. In order to calculate variables, test hypotheses, and perform other statistical tests, Limer, Hausman, Breusch-Pagan/Cook-Weisberg tests and Eviews software are used. The results indicate that there is a significant relationship between the auditor's specialization and information quality of companies listed in Ajman Stock Exchange and there is a significant relationship between auditor's specialization and investment efficiency of companies listed in Ajman Stock Exchange.
