Abstract: A machine for producing a high viscosity dyeing sizing. A sizing boiler is provided in the upper portion of the machine body for boiling an initially provided liquid with steam while agitating it sufficiently with stirring frames, stirring rods and a plurality of blades to produce a high viscosity sizing. The boiler is connected with a cylinder in the lower portion of the machine body, and a piston is movable in the cylinder for sucking the sizing from the size boiler into the cylinder and discharging it therefrom. The piston forces the sizing to pass through a straining screen provided in the front end of the cylinder thereby eliminating impurities and producing a sizing paste of good quality.