PURPOSE: To improve the strength of the eyeless needle and to improve the passability to the biotissue by forming a caulking part and a reduced diameter part at a base end when suture is inserted into the blind hole of the base end and the base end is caulked and forming the juncture thereof to a curved shape when suture is inserted into the blind hole of the base end.

CONSTITUTION: The suture 4 is bonded to the eyeless needle 3 and the molded part 5 consisting of the caulking part 5a and the reduced diameter part 5b is formed as the continuously curved shape in the base end 3a without having a discontinuous part. Then, angles are not formed in the eyeless needle 3 caulked at the base end 3a by the caulking die A and the stress concd. part in the molded part 5 of the needle 3 is eliminated. In addition, the passability through the tissue is improved. Since the caulking part 5a and the reduced diameter part 5b are molded to the continuously curved shape, the extreme drawing of the blind hole in this part is obviated and the cutting of the suture 4 when the blind hole is inserted is prevented. A heat-treated carbon tool steel or a material, such as tungsten carbide, having nigh hardness, is used as the material to constitute the caulking part.