North West of Iran with its appropriate climate condition and neighborhood with Anatolia, Mesopotamia, and Naxcevan, had a particular importance in archeology of different prehistoric and historical periods. Most studies concerned to proto-history and historical period, and prehistoric studies are limit. Excavations results of Hajji-Firuz and Dalma show that there is a gap between them. According to new research, possible to say that this gap is not seen or it is less evident. Despite the vastity of Halaf culture in Mesopotamia and adjacent regions, but in Solduz plain it is not seen evidence of Halaf culture. Another considerable case is identifying Uruk pottery in this area. Based on new finds, propose new chronology for southern urmia basin. It seems that in the Zab basin there is evidence that all of these cultures fill the gaps in the chronological and cultural continuity of the northwest of Iran, or at least the south of the Urmia Lake basin. Between 2010 and 2011 I was able to survey this area. The summery of Chalcolithic sites research is presented here. 32 Chalcolithic Settlements are known in the Zab basin. Settlement patterns and size of sites does not approve the social stratification, tangible political, economic or religious organization in this area. It must be noted that, however some of these cases do not provide much evidences of a cultural presence, for example Uruk culture in the Solduz plain, but this may be due to a lack of research in these areas up to this point.
