Tertiary volcanic rocks are found in the southern flanks of Central Alborz Mountains, in the north of Tehran. Their composition ranges from basalt to rhyolite. They range from low-K rocks to calk-alkahne, high-K calk-alkaline and Shoshoni tic series and show subduction-related geochemical characteristics.Investigation of chemical analysis of major oxides and a vast range of trace elements of the rock samples of the region show that geochemical characteristics of these rocks have great similarities with those of volcanic arcs in the destructive plate margins. More enrichment in alkaline, alkaline earth elements, and Th with respect to N-MORB and depletion in HFSE (Ta, Nb, Zr, and Hi) relative to LREE are characteristics of the rocks of this region. The volcanic rocks are thought to be derived from a homogeneous mantle source modified by slab-derived melts and/or fluids and a small fraction of oceanic sediment.