To contribute to the relaxation of the rigidity of an endless part by dividing the overlap part of a steel cord row over a plurality of times to supply unvulcanized rubber and dividing this rubber from one end side over a plurality of times to successively vulcanize and mold the same.

A rubber elastomer 1 is set to a dimension slightly shorter than the total length of an obtained rubber crawler and steel cord rows 2 are protruded from both ends thereof. The rubber elastomer 1 may be vulcanized by any vulcanization method. The protruding parts 2a, 2b of the steel cord row 2 is allowed to overlap with each other and a new unvulcanized rubber 4 shorter than the overlap part 3 is charged to the overlapped part to be vulcanized and, by successively performing the vulcanization process over a plurality of times, an endless part is completed. A large-scaled equipment is required in the case of a usual molding method vulcanizing and molding the overlap part 3 as a whole at once is required but, in the case of this molding method, a small-sized vulcanizing equipment is sufficiently used and cost is reduced.