Abstract: Provided is a door hinge assembly including hinges each comprising upper and lower connecting units each comprising a plate secured to door or door frame, and a cylinder having a toothed bore; a first rotational unit inserted into the cylinder of the upper connecting unit and comprising a first slope; and a second rotational unit comprising an upper shaft snugly inserted into the first rotational unit, a second slope, and a lower cylinder having a toothed surface inserted into the cylinder of the lower connecting unit. The first slope of each hinge engages the second slope thereof when the hinges are not swung. The upper connecting unit of each hinge swings from a closed position to an open position by pushing. The first slope moves from the highest point of the second slope to the lowest point thereof in response to releasing the pushing force for closing the door.