A decorative sheet wherein the strength of a gypsum sheet or a base paper-pasted gypsum sheet constituting a base sheet of the decorative sheet is improved by impregnating a core member of the gypsum sheet or base paper-pasted gypsum sheet with reinforcing fibers, and further improving the inter-layer strength of the base paper of the base paper-pasted gypsum sheet, or improving the bulk density of the gypsum sheet, whereby the warpage of the decorative sheet which occurs when a resin decorative layer is provided on these base sheets of the decorative sheet can be prevented with a very high efficiency.
