Disclosure is a cutter holder device for a pelletizer in which a cutter shaft is coupled to a cutter holder through a crowned involute spline gear and an elastic member so that cutter blades are kept in close contact with a die surface. In the cutter holder device, the cutter shaft is coupled to the cutter holder through the crowned involute spline gear and the elastic member, so that, even when a squareness between the cutter shaft and the die surface is lowered, all cutter blades are held in close contact with a die surface, whereby the resultant pellets are satisfactory and uniform in configuration.