ABSTRACT: Studies in the recent years have estabüshecl that the strontium laotoplc ratio» (8îSr/S6İr)measured in igneous rocks have considerable contributed to the attempts aiming to light up the genetteproblems of these rocks. In this paper, these studies are summarized, their appUeations to the Cenozolcvolcanic rocks In the Aegean and in West Anatolia are stated, and the genetic problems and mapnaicevolutions of these voloanles are discussed. The Sr lsotopic ratio measurements earned out in the PlioQuaternarY island are volcanic» found in the Aegean sea have revealed that this arc wleaiiism hasa much greater 8?Sr/86Sr content than those of other island arcs in the world, and that this ratio alsoshows differences locally from one point to another. On the lother hand, the Sr isotope measurement»conducted in the Cenozoie volcanic rocks of West Anatolia Imply that voieamsm in this region k notmonogenic, and that there is a mantle-crust relationship.