The paper describes the technology of welding the rails in a long tape. Nowadays, the welding of rails and switches in the long tapes is necessarily when laying new track, and preferably on existing tracks, if the rails are not too worn, the undercarriage is stable, and the track is properly regulated according to the directionand the level. Rail welding can be done in four ways. Resistance welding, nowadays, represents the cheapest, the fastest and the highest quality welding process. Aluminothermic welding process is very simple one because it requires relatively little and light equipment. The time required for welding is very short. By the term -arc welding, it is meant welding processes which use an electric arc as an energy source between the electrode and the base material. On the other hand, autogenic (gas) welding rails uses the property of acetylene to give a flame of temperature above 3000 degrees of Celsius when combustion in oxygen. A maintaining of long strips of rails requires knowledge of their operation in various temperature regimes, in maintenance works that alter the state of resistance in the permanent way, as well as control of the behavior during exploitation