PURPOSE: To effectively prevent generation of the reel mark and to reduce the line stop time by coiling a partial buffer material in a fixed condition at the position corresponding to the coiling end part of the strip.

CONSTITUTION: In coiling a strip 2 by a belt wrapper 4 to a reel 1 where a rubber sleeve 10 is mounted, a partial buffer material 3 is fixed by keeping the distance L equal to πD to the coil inner diameter D to be formed by being coiled from the end of the strip 2. Coiling is started in the fixed condition of this buffer material 3. And a coil is formed so that the partial buffer material 3 may be coiled in a joining manner to a locking part. The thickness of the buffer material 3 which can reduce the local pressure during the coiling operation from the steps at the end of the strip 2 is employed.