One of the important considerations to establish an air pollution control system is the choice of the location of air pollution monitoring stations. Air quality monitoring sites should be located in somewhere the system represents the real condition of air quality and provides real-time data for decision makers. In the present paper this issue is carried out for great Tehran. The number of stations required for Tehran is estimated 56 sites using the number of stations per population of some development countries (in the area of air quality monitoring). At the moment 12 stations (7 for Department of Environment (DOE) of Iran, 4 for Air Quality Control Company (AQCC) and one for Ministry of Health (MOH)) are available in Tehran for air quality monitoring. Accounting this number of stations, 44 new stations are necessary. Using definition of neighborhood scale, 8 of 44 sites are located in neighborhood area of Tehran. The remained 36 stations are located in dense scale with the aim of the correlation analysis of existing DOE sites data (during 6 years). The analysis illustrates the decrease of correlation coefficients toward west and south respect to central station (Villa station) are greater than that those for east and north direction. Based on this correlation analysis, the sites are located in dense scale so the number of stations in west and south area of the central station is more than the other areas.
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