The end of the year 1992 signals harmonisation of technical rules and regulations throughout the Common Market (The European Community, EC). This also has profound consequences for welding. Of the order 150 European standards for welding are in various stages of preparation; many of these will be implemented before the end of 1992. And it is only the beginning. Much of the work is, of course, based on existing national or international standards, but the mere fact, that a standard has been in use in a sigle country for years does not necessaryly mean that it is suitable as a European standard. European standard must fit into a European framework. The paper presents the structure and overall work programme of CEN/TC 121, the European Committee for Standardisation in Welding. The emphasis is laid on essential concepts which have been defined by TC 121 and which together outlines the principles for the European standards for welding.