Labour relations in Japan were very unstable and even hostile in the immediate Postwar period. There were so many cases where even the right to manage was not secured in that period. It is trough the period of economic high growth, from 1955 to 1973, that industrial relations was drastically stabilized. A lot of large scale and prolonged labour disputes occurred in the process of stabilization. One of the distinct characteristic of Japanese industrial relations has been enterprise-based union. This paper aims to clarify the formation process of ``stable and cooperative`` industrial relations during the high economic growth period. It investigates into the formation process and functional characteristics of the post-war enterprise unionism which resulted directly from the collapse of ``the cross-enterprise industrial union movement`` and shop floor struggle(``Shokuba-Toso``) shop in the 1950`s and 60`s. In particular, functions of enterprise union and its changes are discussed under the theoretical framework in which the concept of ``joint consultation`` is to be differentiated from that of ``collective bargaining``.