As the science of accounting and presentation of new evaluation models has been progressed, an improvement in the position of accounting information in evaluation of the companies by investors is expected. This study by choosing a sample of the companies listed on the Tehran Stock Exchange examines the process of the price model and its elements 1993-2010. The results of research show that the price model in the examined period has been significant. after controlling the special factors of the company, according to the results, the relation between earning per share and the price per share has not significant changes during the time, but the relation between book value of equity per share and price per share and both earning per share and book value per share related to the price per share is significantly decreased during the research period. The study of the changing relation between variables before and after mandatory adoption of Iran accountings standards and new law of the stock exchange, shows that in both cases there is no significant change for earning per share and book value of equity per share models, but the price model in the post standards and new law period is significantly decreased.

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