To provide an aseismatic reinforced structure for an existing concrete columnar body ensuring that the columnar body is integrated with a lining member when the lining member is wound around the outer peripheral surface of the columnar body via mortar or the like, and capable of enhancing the efficiency of construction work therefor.

A plurality of horizontal circumferential grooves 4 are cut at predetermined intervals in the outer peripheral surface of a columnar body 1 made of concrete and antislip members 5 made of steel are mounted in the circumferential grooves 4 in the form of bands. Mortar 3 or the like is packed between the lining member 2 wound around the outer peripheral surfaces of the antislip members 5 and the columnar body 1. Also, a plurality of overhanging members 6 are mounted on the inner surface of the lining member 2 at predetermined intervals.