PURPOSE: Extreme edge of rib formed in bellows and spiral shape in the outer circumference of a hose is heated and melted to make the position fat and the rigidity of the hose can be improved by simple production process and then required hose having excellent durability can be obtained.

CONSTITUTION: By means of blow forming, bellows and spiral shaped rib 1 is projected in the outer circumference of a hose 2 and after that the space existing between opposed side wall of the rib 1 is pressed and then its extreme edge is thermally fused. Thus, no space between the opposed side wall of the rib 1 is observed and so the edge part forms integrally a thick round part 6. Observing from this process, no special material is not required, but hose durability can be highly improved.