In this article, we study role of accounting information in decreasing of information asymmetry in Tehran Stock Exchange (TSE). Predicted Earning per Share (PEPS) announcement is a type of information that listed companies publish. This paper studies existence of information asymmetric and its effect on stock prices and trading volume 21 days before 21 days after PEPS announcements. Our samples are 121 PEPS announcement in 1381-1383 period. The results show that information asymmetric was been in theat period and its level in the period before announcement was higher than announcement. Also, we found information asymmetry was related to trading volume and stock price, so before the announcement, trading volume was increased and stock price was fluctuated.