Abstract: A door damping system includes a base fixed to a wall, a fixing element fixed to the door and a rod connected between the base and the fixing element, the base having a pinion rotatably disposed in the base and the pinion coupled to the rod and a coil spring, a cylinder having a slidable piston rod which has a first end with a rack which is slidably received in the base for an engagement with the pinion and a second end with a piston slidably disposed in the cylinder in which oil is filled, the piston having a first and a second flanges, the first flange having a gap defined between the first flange and an inner periphery of the cylinder, the second flange having a plurality of fifth holes defined therein and a first clearance being defined between the piston and the piston rod, a ring movably disposed between the first and the second flanges so as to seal the gap when the door is returned and oil can only flow through the first clearance so as to slow down the speed of returning of the door.