Abstract: Disclosed is a method of producing a packaging paper for packaging metallic materials, as well as a packaging material such as corrugated box produced from the packaging paper, the method comprising at least one of the steps of (i) pulping a material by a cooking liquor containing no sulfur compound, or pulping the material by a cooking liquor containing a sulfur compound and then oxidizing the pulp with a peroxide, (ii) conducting the paper making step in the neutral region of pH value ranging between 6 and 8, and (iii) applying a rust-prevention agent and/or a sterilizer to the paper sheet. Disclosed also are a packaging paper and packaging material for packaging metallic materials, produced by the above-mentioned method.