A central heating templet for an underwater granulating machine, which emits the quantity of heat outwardly to the extruding outlet and the surface of the templet so as to maintain the templet and extruding outlet in an increased temperature to get an optimized flow that the melting polymer passes through the extruding outlet. In an embodiment, a heating plate in center is fixed on an upstream face of the templet, facing to the concave portion in the front cone. In the second embodiment, cylinder shaped heating loop is arranged between the front cone at the upstream side and the insulated plug at the downstream side or between the plates, in the templet hollow central borehole. The heating wire extends through a single radial hole in the templet so as to supply the power to the central heating element.