The neolithic settlement of Twann " Bahnhof " has been excavated during the 1970's. It presents successive sets covering nearly all the second part of the IVth millennium. The ceramic set has been published (Die neolitischen Ufersiedlungen von Twann, 20 volumes, between 1977 and 1981). This dwelling is a reference for the lacustrine research. However, far too little attention has been paid to the technological aspects of ceramics. This communication suggests to reexamine many potteries of the site from late Cortaillod to recent western Horgen, in order to study pottery manufacturing and to reconstitute the " chaînes opératoires ". This case study will allow us to abord methodological questions about the constitution of technical groups, production groups and technical traditions. Moreover, the technological study of a selection of characteristic potteries from each layer makes possible the opening of a new talk about the transitional process between middle and Late Neolithic in the Three Lakes region. Indeed, the flattering of bottoms and the reduction of the " esthetic " aspect of potteries are evocated since a long time in litteratur as morphological markers to identifie changes in ceramic production (for example: Hafner and Suter, 2006). So, what about the technological aspects? What is the evolution of technical traditions on one site, during the second part of the IVth millennium? Are they following closely the morphological variations or, on the contrary, can we see different changes between technical and stylistic aspects? Conditions will be reunited to evocate new interpretative propositions about contacts between populations in the Three Lake region during the second part of the IVth millennium.