PURPOSE: To provide a leaf paper tying device which can prevent accumulated leaf papers being pinched from bending due to a natural folding line without extending the length of pinching members.

CONSTITUTION: At the central side of one of pinching members 32, a bar-shaped member 57, which extends at least to the central position in the longitudinal direction of leaf papers 10 under an accumulated condition which are being pinched, and corrects a swelling due to a folding line of the leaf papers 10 at the central position, is provided. By the bar-shaped member 57, the leaf papers 10 are pinched under a condition wherein the swelling due to a folding line is corrected.