The effect of Mandating Accounting Standards on the relevance of reported of Companies Listed in Tehran Stock Exchange

One of the most important purposes of the International Accounting Standards is presenting useful information for decision making. This purpose has been considerably emphasized base on usefulness of financial information for predicting in different standards. In the present study, net profit and book value of the companies is regarded as the representatives of the accounting numbers and their ability have been examined for clarification the market value of the companies in after and before the period of Accounting Standards Requirements. Sample of study consists of 86 companies among accepted companies in Tehran stock market and the period of the study contains 16 consecutive years from 1994 to 2009 which consist of two eight-year periods prior to the Accounting Standards Requirements (1994-2001) and the period after Accounting Standards Requirements (2002-2009). The results of the study confirmed information content of accounting profit. The results also represented that the requirements of Accounting Standards has had significant positive impacts on information content of accounting profit. According to the results, the book values of affiliate's ´wages hasn´t have information content and the requirements of Accounting Standards hasn´t affected on it.