South Caucasus lay among the Iranšahr lands, as a part of cultural Iran during Sasanian era (224 – 651 AD.). According to Sasanian written documents, this area is recognized as Aniran lands. Since the time of Šapur I (241-272 AD.) we see terms such as Iranšahr, Iran and Aniran in Sasanian inscriptions. Application of these new words indicates the conquest of western and northwestern lands of imperial and consequently the relative domination of Sasanians on these areas. The present research tries to answer this question based on archaeological cultural materials and also historical writings that Sasanian realm in south Caucasus has been included which areas? The findings of this research show that the area of south Caucasus during Sasanian era was divided into three extensive ethnic-racial district of Arān, Armin, Wirūzān. Through them, Armenia was more important insofar as Dvin was the center of south Caucasus. In case of Georgia likewise, Sasanian dominated at its eastern section.