PCT No. PCT/JP98/03870 Sec. 371 Date Apr. 27, 1999 Sec. 102(e) Date Apr. 27, 1999 PCT Filed Aug. 28, 1998 PCT Pub. No. WO99/11439 PCT Pub. Date Mar. 11, 1999A perforated separation line forming apparatus which is characterized by: an edged rotary body (2) having a round slitting edge (1); and a receiving rotary body (4) having a receiving circumferential surface (3) that the round slitting edge engages; wherein the edged rotary body (2) and the receiving rotary body (4) are arranged to clamp a perforated line forming position (6) of a continuously fed transfer material (5) therebetween; wherein the receiving circumferential surface (3) of the receiving rotary body (4) is formed with non-slit portion forming recesses (7), which the round slitting edge (1) of the edged rotary body (2) cannot engage, at predetermined intervals in the direction of rotation, so that the perforated separation line (8) formed at the perforated line forming position (6) has slit portions (8A) and non-slit portions (8B) alternated successively; wherein the receiving rotary body (4) is movably adjustable relative to the edged rotary body (2) in an axial direction, the non-slit portion forming recesses (7) of the receiving rotary body (4) are so shaped that a circumferential width of the recesses (7) in the direction of rotation changes in an axial direction of the receiving rotary body (4), and as a result of the relative movement of the receiving rotary body (4) in the axial direction, the circumferential width of the non-slit portion forming recesses (7) in the direction of rotation varies so that a ratio between the slit portions (8A) and the non-slit potions (8B) is variably adjustable.