PURPOSE: To obtain a base of a water-resistant photographic printing paper, superior in whitening effect, by forming a coat of polyolefin contg. a white pigment on a paper base obtained by dyeing low whiteness pulp not above a specified spectral reflectance with a blue dye and giving a reflectance of a specified wavelength not below a specified value to the paper.

CONSTITUTION: A proper amt. of blue dye, such as 0.0004W0.0006wt% of "C. I. Direct Blue ", an amt. of dye depending on the kind of it, is added to a low whiteness pulp having ≤90% spectral reflectance at 440nm wave length to make paper, and the reverse side of the paper is coated with polyolefin including polyethylene. A white polyolefin layer contg. a white pigment, such as TiO2, is formed on the front side, that is, the emulsion coat side, to obtain a water- resistant paper base of a photographic printing paper. The paper base colored with the blue dye is controlled so as to have 85W90% spectral reflectance at 560nm wavelength, thus permitting the obtained paper base to be superior from the point of visual sensation in spite of using no expensive high whiteness pulp.