Abstract: The financial markets by providing liquidity, reducing transactions’ cost through reduction of searching cost and lowering information cost are good place to lead people stagnant savings toward producing and providing economic companies and institutions investment. One of the most important and most popular financial markets in most countries is stock markets. The fluctuations' behavior of stock market has always been discussed and investigated. Due to the importance of stock markets in attracting great and small savings, the discussion on the factors affecting the stock market fluctuations had always been under attention. Hence, this paper intends to examine the relative contribution of impacts of monetary policies on the Tehran Stock Exchange. This research method is descriptive-survey. Since past data of companies and central bank will be used, data collection method is historical. The statistical population consists of all companies listed on Tehran Stock Exchange. Sampling method has been used is cross-cut sampling. Data obtained from cross-cut are prepared at a point of time and randomly. The selected sample is data related to price series and stock return, as well as data related to variables of the government’s monetary policy from 2001-2011. SPSS software and 5 E-views software have been used in order to examine the model and analyze data in this research.The results showed coefficient variable of the government expenditures in the short term is indicative of this point that with the increase in this variable at 1% stock returns is reduced at 0.176 % with a lag. Current values and taxes' lag had a significant negative impact on nominal return of stocks. The current values of the money supply have a significant negative impact (at the critical level of 10%) on current return of stocks. Values with lag of this variable have no impact on current return of stocks. Interest rate coefficient is negative and is also consistent with the theory but not statistically significant. Another result is the positive impact of inflation on nominal return of stocks.