In this paper, the effect of utilizing first urban rail transit on decreasing energy consumption as well as air pollution in Ahvaz has been investigated. The No. 1metro path in Ahvaz with 23 kilometers length will connect the north eastern part of the city to its south western part by passing through the central area and crossing Karun River. At the beginning, some points will be mentioned regarding railway systems around the world and then the specification of Ahvaz No. 1 metro will be introduced. Finally, the amount of decreasing energy consumption and air pollution after utilizing 4 urban metro lines will be investigated. The results have shown considerable effects on decreasing these items.