The Caucasus-Iran-Anatolia (CIA) region in the Tethysides Orogenic belt was elevated by Arabia-Eurasia collision. The Ankara-Erzincan/Sevan-Akera suture zone and the Bitlis-Zagros suture zone in this region stand for the closures of northern and southern Neotethys system since late Mesozoic, and Cenozoic magmatism has been related to the subduction and termination of the Neotethyan system. In Georgia, located at the northern part of the CIA region and north of the Ankara-Erzincan/Sevan-Akera suture zone, the Cenozoic igneous rocks are widespread in the Lesser Caucasus region. This study combines a detailed geochemical analysis of Cenozoic igneous rocks in Lesser Caucasus of Georgia with tectonic events to comprehend the Cenozoic magma mechanism of northern CIA region. The previous research with the zircon U-Pb and whole rock Ar-Ar dating results in this study show that Cenozoic magmatism in Georgia can be divided into four main stages, i.e., middle Eocene (46.8-40.4 Ma), late Oligocene (24.4 Ma), late Miocene (9-5 Ma) and late Cenozoic (< 3 Ma). The first, third and fourth stages consist of basic to felsic rocks, but the SiO2 contents of the Oligocene volcanic rocks range from 58 to 66 wt.%. Rocks of four stages can be subdivide into three groups: middle Eocene calc-alkaline and shoshonitic rocks, late Oligocene adakitic rocks, late Miocene calc-alkaline and adakitic rocks, and the composing of late Cenozoic (< 3 Ma) is the same with the prior stage. Incompatible elements data show that all the Cenozoic igneous rocks display the “arc geochemical signatures” such as enrichment in LILE (e.g., Cs, Rb, Ba, K) and depletion in HFSE (e.g., Ti, Nb, Ta), and the signatures mitigate with stages. The Sr-Nd isotope data and the zircon Hf isotope data indicate that the magma source might be upper mantle. Because of lack of basic type and without assimilation of continental crust, we consider the source of middle Eocene shoshonitic rocks is amphibolitic lower crust. We also suggest the Cenozoic adakitic rocks with low MgO, Ni and Cr concentration are caused by remelting of eclogitized lower crust. Both types of mafic lower crust are form by mantle derived young basaltic underplates at the base of crust. The lithosphere of northern CIA region thickened after the closure of northern Neotethys in late Mesozoic. We think that the middle Eocene calc-alkaline magmatism of Georgia was induced by asthenospheric upwelling result from lithospheric delamination. The calc-alkaline magma provided as a heat source for the partial melting of the amphibolitic lower crust and produced the shoshonitic magma. The magmatism of middle Eocene ceased by Arabian-Eurasian collision after southern Neotethys closed in late Eocene. With the continental collision, the thickened basaltic underplating crust (> 50 km) of Lesser Caucasus transform into eclogite, and remelted into adakitic magma owing to delamination beneath the Lesser Caucasus in late Oligocene, late Miocene and late Cenozoic (< 3 Ma). The large scale of lithospheric removing in late Miocene and late Cenozoic (< 3 Ma) also triggered the widespread calc-alkaline volcanism in Lesser Caucasus of Georgia.