To mount a toilet seat cover to a toilet in the state of being wound in a roll shape by providing a pleat-like extension and contraction part on the center part of respective sections divided by perforation for dividing a sheet into a dimension almost equal to the dimension in a longitudinal direction of a toilet seat in a water soluble sheet suited to the frame width of the sitting part of the toilet seat.

In the case of using this toilet seat cover 1, the toilet seat cover 1 is provided with a cut-out part 5 for which the water soluble sheet 2 is cut out on both sides of the perforation 3, the respective sections are cut off by the perforation at the time of using the cover and a peeling sheet 7 is peeled off by picking the cut-out part 5 with a finger at the time. There, an exposed sticking part 6 is stuck on the toilet seat and one end of the cover 1 is fixed. Thereafter, the pleat-like extension and contraction part 4 is spread matched with the shape of the toilet seat and the other end of the cover 1 is fixed to the other end part of the toilet seat by the sticking part 6. At the time, the pleat-like extension and contraction part 4 is suited to the shape of the toilet seat since the outer side part of the toilet seat is spread more than an inner side part. Also, after using the toilet, the toilet seat cover 1 is peeled off from the toilet seat and abandoned inside a stool.