The transition from the Neolithic to the Bronze Age, which is usually linked to the Chalcolithic, is still not well understood in Central Asia. In the current state of research on the neolithisation processes, which happen in this region between the 10th and the 3rd millennium, we wish to propose different definitions according to the societies under study. There is something to suggest that it as either a relatively short (Botaj, Northern Kazakhstan) or a long development (Namazga I-IV, Southern Turkmenistan) during which the local Neolithic tradition evolve into Bronze age; in the dry, piemont or steppe regions with tugai forests (Uzbekistan and Northwestern Tajikistan), it is rather a transitional period, marked by contacts between Kel’teminar Neolithic groups and contemporaneous Early Bronze Age communities. Sites located along the Zeravshan River are a very good illustration of the latter situation. We will focus here on some of the recently results, yielded by the techno-typological study of the lithic industry from the agropastoral settlement of Sarazm, dated to the Chalcolithic and Early Bronze Age (4th-3rd mill.). This material deserves particular attention since it helps to define the specific cultural identity of Sarazm inhabitants, and to discuss the mechanisms and dynamics of the complex interaction between contemporaneous communities with different lifestyles such as those from Kazakhstan, Uzbekistan, or even Siberia. The presence of some specific pieces and techniques, as well as of a great number of raw materials which reveal different geographical provenances, confirm the existence of a broad network of relationship; Sarazm would be one of the nodal points of this net.