With the beginning of the 3rd millennium the emergence of complex societies in Central Asia are observed next to the great cultures of Mesopotamia, Elam and Indus. Central Asia has formed a crossroad for millennia between the East and the West. The region exhibits a high genetic, ethnic and linguistic diversity and played a key role in linking cultures. Stable isotopes analyses of human and animals remains provide data on the origin of individuals, the mobility during lifetimes, the subsistence of people, and the climatic conditions of the investigated region. The results indicate the composition of populations and the rate of migration. Respectively information about sedentism or mobility of human populations and external cultural influences within societies can be reconstructed. The talk will present isotope analyses of several sites in Turkmenistan, Uzbekistan, Tajikistan and Iran. Focus are the Bronze Age communities of Ulug Depe on the foothills of Kopet Dagh and Dzharkutan in the southern valley of Surchandarija River. The two sites represent the complex society systems of the Oxus Civilisation. Archaeological remains show fortification walls, living quarters, storage and handcrafts areas, and huge monumental buildings interpreted as palaces and temples. The data argue for strong social hierarchies as well as a larger exchange network to the neighbouring civilisations. The question to be answered is what the results of isotope analyses can tell us about these still enigmatic populations?