To provide a decorative sheet for an indoor floor which hardly allows its surface layer to float or separate, is not flawed by a metal foil, has a good construction workability, and exhibits cushioning properties/thermal insulation properties after construction; a floor construction structure; and a floor construction method of a decorative sheet for an indoor floor.

This decorative sheet 4 for an indoor floor is prepared by laminating a flexible double-coated pressure-sensitive adhesive sheet 4 with a thickness of at least 0.5 mm, via a soft film 2, to the pressure-sensitive adhesive surface of a decorative sheet 3 comprising a resin sheet having a surface decorativeness on one side and a pressure-sensitive adhesive layer formed on the other side. The floor construction structure of the decorative sheet for an indoor floor is built by laminating by sticking the pressure-sensitive adhesive surface of the double-coated pressure-sensitive adhesive sheet 1, the surface being at the side reverse to the soft film, to the indoor floor surface. The floor construction method of the decorative sheet for an indoor floor comprises laminating by sticking the decorative sheet 4 for an indoor floor to the surface of an indoor floor.