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Arbitrage Pricing Theory (APT) was introduced by Ross in 1976. The fundamental assumption of this theory is the absence of arbitrage in the stock market. In this theory, the price of an asset is determined according to its level of risk and several macro-factors explain the level of the risk of a given asset. The main target of this study is investigating the conditions in which APT can be implemented in Tehran Stock Market. The stock price data of 20 firms active in stock market and six important economic indices were collected and used in this study. The SUR estimation method has been used for estimation of the equations system and for testing APT conditions the LR statistics have been used. Finally, having investigated the issue and data, adoption of APT in Tehran Stock Market was not rejected by the study.