Abstract: A safety hypodermic syringe includes a barrel having a receiving hole, a needle holder slidably and controllably disposed therein and having an insertion hole, an inner tapered hole, a pull stop edge located between the insertion hole and the inner tapered hole, and a liquid transporting hole in communication with a hypodermic needle; a plunger having a rod body, a connection head of a conical shape cooperative with the inner tapered hole, two claws capable of retaining the pull stop edge of the needle holder, and two notches formed in opposite inner side of each claw; wherein the plunger and the needle holder are in intimate cooperation to provide a minimum residue of liquid drug, the claws serving to catch and pull the pull stop edge of the needle holder, so as to enable the plunger to draw the needle holder and the hypodermic needle into the receiving hole of said barrel.