Thrace is a historical and geographical region in the southeast of Europe. This region divides between Turkey (East Thrace), Greece (West Thrace) and Bulgaria (North Thrace). The region called East Thrace is in the northwest of Turkey. There are five cities in this region: Edirne, Kırklareli, Tekirdağ, Istanbul (European side) and Çanakkale (Only Gelibolu region). Before the Ottomans, Greeks, Persian Empire, Roman Empire, Goths, Visigoths, Slavic communities, Bulgarian Khaganate, and The Byzantine Empire ruled in this region. Greek cities like Bosphoros, Byzantion, Propontis, Khersonesos, Abdera, and Ainos; Roman cities like Hadrianapolis (present-day Edirne) and Serdica (present-day Sofia) were important economic and cultural centers. The east branch of Rumelia dialect is spoken in the cities, which are in this region. Generally in East Trace, “Gacals”, “immigrants from Bulgaria, Greece, Romania, Yugoslavia (former)”, “Tatars”, “Pomaks”, “Dağlılar” (Mountaineers), “Yörüks”, “Gypsies”, “Bosnians” live and speak a kind of Turkish dialect. East Thrace is a socio-economic route between Asia and Europe as it is in the past Latterly East Thrace is on the target of internal migration..According to the 2000-2017 population increase datas, the population of Edirne has increased from 392.134 to 406.855, the population of Kırklareli has increased from 323.437 to 356.050, and the population of Tekirdağ has increased from 577.812 to 1.005.463. Because of that, East Thrace dialects are in danger of extinction. We should immediately conduct field works and collect the language materials and search ethnonyms, toponyms, micro-toponyms, zoonyms and fitonyms. We should classify Ottoman tombstones and epitaphs and collect the folkloric materials