This study investigates monthly mean distribution of tropospheric ozone in different layers of the troposphere during the period 2012-2016, which is considered as an important and complex gas in the atmosphere. To this end, the CAMSRe (Copernicus Atmosphere Monitoring Service reanalysis) data derived from the third ECMWF project in the field of atmospheric chemistry are used. Results indicated that maximum concentration of ozone in different layers of the troposphere occurs in summer in which different sources have contributed. Maximum concentration of ozone in lower layers is mostly attributed to anthropogenic sources, while high ozone concentration in upper layers of the troposphere is primarily caused by descending of the stratospheric air associated with large-scale meteorological systems.