A new process of dry carbon fibre fabrics (NCF's) preforming has been developed for composite stringers of aeronautical structural parts using an adaptive mould. The new process consists of straight stringer preform manufacturing of known section in a conventional way, applying tensions, deformations and variations of pressure and temperature by means of an adaptive mould to achieving the final geometry. This preform will be consolidate by liquid moulding. The behaviour of the preform will be evaluated analysing the formation of wrinkles both internally and externally. Finally, a new prototype has been designed and manufactured and the automation of this new process has been initiated.