The existence of a contractual element in the begining of the responsibility of the producer in the present century suggests a necessary reference to the contractual law of XIX C. Unlike the XVIII C. in which, is extremely difficult to reach a total knowledge of common law, due scarc number of judicial issues and the almost nonexistent importance of the judicial precedent, in XIX C. is atended to a deep change due to the economic expansion. This phenomenon determined a parallel increase of the judicial issues, great part of which had like foundation the bad quality of the sold product. This period, characterized by the movement in the economic operations that the industrial development, becomes the context ad hoc for the diffusion and the consolidation of the principle of privity of contract that in the systems of written right comes to correspond at the beginning of ‘relativity contractual’.