Abstract: A safety syringe is particularly equipped with a needle receiving tube which safely facilitates the mounting and dismounting of a disposed needle. The safety syringe has a container, an injection rod, a needle and a needle receiving tube. The needle can be withdrawn into the container via rotation of the injection rod after being used for disposal so as to protect hospital personnel from being accidentally punctured by a disposed needle which can cause fatal contagion of various diseases. The container is provided with a protruded needle mounting neck having a lid attached to the edge thereof. The injection rod housed in the container has a rubber piston head which is provided with a plunger end. The plunger end is made up of 4 symmetric plane extensions each having a round projection on the edge of each plane extension.