The present invention relates to a preparation for a polyurethane foam and a polymer polyol preparation for polyurethane foam, each of which exhibits high coloration and discoloration suppression properties when stored for a long time, and a composition for a polyurethane foam, which has excellent storage stability and which is suitable as a resin premix. This composition for a polyurethane foam is characterized by containing (i) at least one type of polyol selected from among a polyoxyalkylene polyol and a polymer polyol obtained by dispersing polymer microparticles, which are obtained by polymerizing a compound having an unsaturated bond, in the polyoxyalkylene polyol, (ii) a compound having a P=N bond, (iii) an anti-oxidant having a hydroxyphenyl group, (iv) at least one type of acid selected from among the group comprising an acyclic aliphatic monocarboxylic acid having 2 to 25 carbon atoms, a polyhydric carboxylic acid having 20 to 60 carbon atoms, a specific aromatic monocarboxylic acid, a sulfonic acid and an acid having a sulfate ester group, or a salt thereof, (v) a catalyst for producing a polyurethane foam, and (vi) a foaming agent.