An impact absorbing barrier assembly comprising: a support having a pipe configuration and installed upright at a center line or a side of a road at constant intervals to other supports; an impact absorbing cylinder rotationally combined to the support and including a cylinder having a through-hole penetrating the cylinder from an upper portion to a bottom portion thereof and being made by using one of ethylene vinyl acetate and soft polyurethane, and including a rotation support pipe having a pipe configuration corresponding to an outer circumference of the support and inserted into the through-hole of the cylinder by force, characterized in that the impact absorbing barrier assembly further comprises: a fence guide horizontally installed at a lower and front portion of the impact absorbing cylinder; a fence guide horizontally installed at a lower and rear portion of the impact absorbing cylinder; a fence guide horizontally installed at an upper and front portion of the impact absorbing cylinder and; a fence guide horizontally installed at an upper and rear portion of the impact absorbing cylinder; wherein said fence guides connect the supports; said fence guides provided at the lower portion of the impact absorbing cylinder support the impact absorbing cylinder, while said fence guides provided at the upper portion of the impact absorbing cylinder prevent separation of the impact absorbing cylinder; the impact absorbing barrier assembly also comprising: a fence guide combining device for combining the correspondig fence guides at the front and rear portions of the support; and a rotation support device of the impact absorbing cylinder, inserted into the outer circumference of the support between the lower fence guides and the impact absorbing cylinder to support rotation of the impact absorbing cylinder. a support having a pipe configuration and installed upright at a center line or a side of a road at constant intervals to other supports; an impact absorbing cylinder rotationally combined to the support and including a cylinder having a through-hole penetrating the cylinder from an upper portion to a bottom portion thereof and being made by using one of ethylene vinyl acetate and soft polyurethane, and including a rotation support pipe having a pipe configuration corresponding to an outer circumference of the support and inserted into the through-hole of the cylinder by force, characterized in that the impact absorbing barrier assembly further comprises: a fence guide horizontally installed at a lower and front portion of the impact absorbing cylinder; a fence guide horizontally installed at a lower and rear portion of the impact absorbing cylinder; a fence guide horizontally installed at an upper and front portion of the impact absorbing cylinder and; a fence guide horizontally installed at an upper and rear portion of the impact absorbing cylinder; wherein said fence guides connect the supports; said fence guides provided at the lower portion of the impact absorbing cylinder support the impact absorbing cylinder, while said fence guides provided at the upper portion of the impact absorbing cylinder prevent separation of the impact absorbing cylinder; the impact absorbing barrier assembly also comprising: a fence guide combining device for combining the correspondig fence guides at the front and rear portions of the support; and a rotation support device of the impact absorbing cylinder, inserted into the outer circumference of the support between the lower fence guides and the impact absorbing cylinder to support rotation of the impact absorbing cylinder. a fence guide horizontally installed at a lower and front portion of the impact absorbing cylinder; a fence guide horizontally installed at a lower and rear portion of the impact absorbing cylinder; a fence guide horizontally installed at an upper and front portion of the impact absorbing cylinder and; a fence guide horizontally installed at an upper and rear portion of the impact absorbing cylinder; wherein said fence guides connect the supports; said fence guides provided at the lower portion of the impact absorbing cylinder support the impact absorbing cylinder, while said fence guides provided at the upper portion of the impact absorbing cylinder prevent separation of the impact absorbing cylinder; a fence guide combining device for combining the correspondig fence guides at the front and rear portions of the support; and a rotation support device of the impact absorbing cylinder, inserted into the outer circumference of the support between the lower fence guides and the impact absorbing cylinder to support rotation of the impact absorbing cylinder.