To provide a joint for bar-shaped body capable of maintaining a strong coupling construction even when a flexural stress or vibration is applied to a butted portion of the bar-shaped body such as reinforcing bar or the like.

A longitudinal through-hole 11 for inserting a bar-shaped body is made, a joint main body 1 is formed with a pair of lateral through-holes 12 having an interval slightly smaller than the outer diameter of the bar-shaped body 3 sandwiching longitudinal through-holes 11 respectively at both the sides of the center of the longitudinal direction, a channel-shaped inserting body 2 is also provided, and each side plate 21 of the inserting body 2 is forcefully inserted from a lateral through-hole 12 in the joint main body 1 to a narrow gap between the inner wall of the joint main body and the bar-shaped body 3. Irregular vertical grooves 21a are formed in the inner surface of each side plate 21. Distance between opposite wall surfaces of the side plate 21 becomes larger toward the end portion of the side plate and the depth of the irregular vertical grooves 21a becomes shallow toward the end portion of the side plate.