To provide a shock-absorbing liner for helmet, having high shock-absorbing performance, needing no expensive mold and producible at low cost, and to provide a method for producing the liner.

The method for producing the shock-absorbing liner comprises the following way: V-shaped notches 28 are formed on a molded form 20 molded with a mold in advance, the resultant molded form is bent so that the oblique sides of the notches 28 are mutually contacted with each other, the pairs of mutually contacted oblique sides are then heated and welded by a heating element and temperature is then allowed to fall with the status left intact. Then, the welded oblique sides are firmly set, enabling the molded form 20 as a whole to be formed to a curved shape with a predetermined curvature.