Multi-Directional Torsional Hysteretic Damper as an anti-seismic device of hysteretic type with multi-directional action for protection of structures against earthquakes characterized in that, it is composed of; • at least eight yielding identical cores, in the shape of variable-diameter cylinder, which can yield, serving as energy dissipating elements by yielding due to large torsional shear stresses created via arms welded to them, while the arms rotate back and forth and create torsion in the yielding cores, with each of the yielding cores having one arm welded to it at its top and with each of the yielding cores being welded to a base plate at its bottom and maintaining a torsional hinge connection with a plate diaphragm, in the shape of an octagon, through the use of core ball bearings at the yielding cores - plate diaphragm connection, • a supporting structure composed of a supporting column and the plate diaphragm, the function of which is to support the yielding cores against bending by taking the major share of the bending moment and thus preventing excessive bending in the yielding cores which are intended to yield in torsion while being twisted by the rotation of the arms, • a rail system comprising identical rails in the shape of a channel section in the same number as the yielding cores plus an octagonal top plate, with the rails welded to the top plate while being positioned parallel to the arms, the function of which are guiding the movement of the arms at the arm's end points where arm ball bearings are provided to create, in combination with the rails, a roller hinge type connection between the arms ends and the structure to be protected, • the arm ball bearings being mounted on cylindrical mounting shafts at the end points of arms and being held in place by upper hollow cylindrical rings and bottom hollow cylindrical rings while the upper hollow cylindrical rings are welded at top to the cylindrical mounting shafts, • top plate being provided with slotted holes which provide the connection of the Multi-Directional Torsional Hysteretic Damper to a bridge deck. • at least eight yielding identical cores, in the shape of variable-diameter cylinder, which can yield, serving as energy dissipating elements by yielding due to large torsional shear stresses created via arms welded to them, while the arms rotate back and forth and create torsion in the yielding cores, with each of the yielding cores having one arm welded to it at its top and with each of the yielding cores being welded to a base plate at its bottom and maintaining a torsional hinge connection with a plate diaphragm, in the shape of an octagon, through the use of core ball bearings at the yielding cores - plate diaphragm connection, • a supporting structure composed of a supporting column and the plate diaphragm, the function of which is to support the yielding cores against bending by taking the major share of the bending moment and thus preventing excessive bending in the yielding cores which are intended to yield in torsion while being twisted by the rotation of the arms, • a rail system comprising identical rails in the shape of a channel section in the same number as the yielding cores plus an octagonal top plate, with the rails welded to the top plate while being positioned parallel to the arms, the function of which are guiding the movement of the arms at the arm's end points where arm ball bearings are provided to create, in combination with the rails, a roller hinge type connection between the arms ends and the structure to be protected, • the arm ball bearings being mounted on cylindrical mounting shafts at the end points of arms and being held in place by upper hollow cylindrical rings and bottom hollow cylindrical rings while the upper hollow cylindrical rings are welded at top to the cylindrical mounting shafts, • top plate being provided with slotted holes which provide the connection of the Multi-Directional Torsional Hysteretic Damper to a bridge deck.