A disposable syringe including: a syringe cylinder (100) for containing a medicinal liquid therein, in which a medicinal liquid nozzle (120) is formed as a protrusion at a front end of the syringe cylinder, and a piston (110) is provided inside the syringe cylinder and a medicinal liquid injection hub (200) including a needle (210) and a needle hub (220) and combined with the medicinal liquid nozzle in a removable manner, wherein a combining part (300) is provided in the medicinal liquid nozzle (120) and in the needle hub (220) so as to prevent a leakage of the medicinal liquid and to allow the needle hub to be both easily separated from and easily combined with the medicinal liquid nozzle by a user when using the syringe without allowing the needle hub to be undesirably separated from the medicinal liquid nozzle.
