To provide a removable ring-bound booklet having no fear of allowing a sheet to come off when being used by an ordinary using method, allowing a sheet to be bound again when the sheet comes off from the binding member and allowing a new sheet to be easily bound.

By providing a cutting line 9 to be cut in toward a binding hole 3 from a side edge 2 of the paper sheet 1 along one side edge of each binding hole 3, both end part of a T-shaped margin part 11 are protruded long in both side directions and a hooking piece 6 to be inserted through the binding hole 3 is stably hooked inside both end parts of the deep T-shaped margin part 11 so that the sheet is prevented from easily coming off.